fa directory created

2018-05-27 18:16:37 +04:30
parent 3eb589a71c
commit 8e905d75f5
469 changed files with 17013 additions and 0 deletions
--- a/fa/code/readme.md
+++ b/fa/code/readme.md
@@ -0,0 +1,7 @@
+## Workspace setup.
+
+To avoid workspace issues and be able to develop from any folder within this path,
+set the environment variable `GOPATH` to the path of this directory.
+
+More info:
+- [GOPATH documentation](http://golang.org/doc/code.html#GOPATH)
--- a/fa/code/src/apps/ch.1.2/main.go
+++ b/fa/code/src/apps/ch.1.2/main.go
@@ -0,0 +1,14 @@
+// Example code for Chapter 1.2 from "Build Web Application with Golang"
+// Purpose: Run this file to check if your workspace is setup correctly.
+// To run, navigate to the current directory in a console and type `go run main.go`
+// If the text "Hello World" isn't shown, then setup your workspace again.
+package main
+
+import (
+	"fmt"
+	"mymath"
+)
+
+func main() {
+	fmt.Printf("Hello, world.  Sqrt(2) = %v\n", mymath.Sqrt(2))
+}
--- a/fa/code/src/apps/ch.2.1/main.go
+++ b/fa/code/src/apps/ch.2.1/main.go
@@ -0,0 +1,11 @@
+// Example code for Chapter ? from "Build Web Application with Golang"
+// Purpose: Hello world example demonstrating UTF-8 support.
+// To run in the console, type `go run main.go`
+// You're missing language fonts, if you're seeing squares or question marks.
+package main
+
+import "fmt"
+
+func main() {
+    fmt.Printf("Hello, world or 你好，世界 or καλημ ́ρα κóσμ or こんにちは世界\n")
+}
--- a/fa/code/src/apps/ch.2.2/main.go
+++ b/fa/code/src/apps/ch.2.2/main.go
@@ -0,0 +1,277 @@
+// Example code for Chapter 2.2 from "Build Web Application with Golang"
+// Purpose: Goes over the assignment and manipulation of basic data types.
+package main
+
+import (
+	"errors"
+	"fmt"
+)
+
+// constants
+const Pi = 3.1415926
+
+// booleans default to `false`
+var isActive bool                   // global variable
+var enabled, disabled = true, false // omit type of variables
+
+// grouped definitions
+const (
+	i         = 1e4
+	MaxThread = 10
+	prefix    = "astaxie_"
+)
+
+var (
+	frenchHello string      // basic form to define string
+	emptyString string = "" // define a string with empty string
+)
+
+func show_multiple_assignments() {
+	fmt.Println("show_multiple_assignments()")
+	var v1 int = 42
+
+	// Define three variables with type "int", and initialize their values.
+	// vname1 is v1, vname2 is v2, vname3 is v3
+	var v2, v3 int = 2, 3
+
+	// `:=` only works in functions
+	// `:=` is the short way of declaring variables without
+	//  specifying the type and using the keyboard `var`.
+	vname1, vname2, vname3 := v1, v2, v3
+
+	// `_` disregards the returned value.
+	_, b := 34, 35
+
+	fmt.Printf("vname1 = %v, vname2 = %v, vname3 = %v\n", vname1, vname2, vname3)
+	fmt.Printf("v1 = %v, v2 = %v, v3 = %v\n", v1, v2, v3)
+	fmt.Println("b =", b)
+}
+func show_bool() {
+	fmt.Println("show_bool()")
+	var available bool // local variable
+	valid := false     // Shorthand assignment
+	available = true   // assign value to variable
+
+	fmt.Printf("valid = %v, !valid = %v\n", valid, !valid)
+	fmt.Printf("available = %v\n", available)
+}
+func show_different_types() {
+	fmt.Println("show_different_types()")
+	var (
+		unicodeChar rune
+		a           int8
+		b           int16
+		c           int32
+		d           int64
+		e           byte
+		f           uint8
+		g           int16
+		h           uint32
+		i           uint64
+	)
+	var cmplx complex64 = 5 + 5i
+
+	fmt.Println("Default values for int types")
+	fmt.Println(unicodeChar, a, b, c, d, e, f, g, h, i)
+
+	fmt.Printf("Value is: %v\n", cmplx)
+}
+func show_strings() {
+	fmt.Println("show_strings()")
+	no, yes, maybe := "no", "yes", "maybe" // brief statement
+	japaneseHello := "Ohaiyou"
+	frenchHello = "Bonjour" // basic form of assign values
+
+	fmt.Println("Random strings")
+	fmt.Println(frenchHello, japaneseHello, no, yes, maybe)
+
+	// The backtick, `, will not escape any character in a string
+	fmt.Println(`This 
+	is on
+	multiple lines`)
+}
+func show_string_manipulation() {
+	fmt.Println("show_string_manipulation()")
+	var s string = "hello"
+
+	//You can't do this with strings
+	//s[0] = 'c'
+
+	s = "hello"
+	c := []byte(s) // convert string to []byte type
+	c[0] = 'c'
+	s2 := string(c) // convert back to string type
+
+	m := " world"
+	a := s + m
+
+	d := "c" + s[1:] // you cannot change string values by index, but you can get values instead.
+	fmt.Printf("%s\n", d)
+
+	fmt.Printf("s = %s, c = %v\n", s, c)
+	fmt.Printf("s2 = %s\n", s2)
+	fmt.Printf("combined strings\na = %s, d = %s\n", a, d)
+}
+func show_errors() {
+	fmt.Println("show_errors()")
+	err := errors.New("Example error message\n")
+	if err != nil {
+		fmt.Print(err)
+	}
+}
+func show_iota() {
+	fmt.Println("show_iota()")
+	const (
+		x = iota // x == 0
+		y = iota // y == 1
+		z = iota // z == 2
+		w        // If there is no expression after constants name,
+		// it uses the last expression, so here is saying w = iota implicitly.
+		// Therefore w == 3, and y and x both can omit "= iota" as well.
+	)
+
+	const v = iota // once iota meets keyword `const`, it resets to `0`, so v = 0.
+
+	const (
+		e, f, g = iota, iota, iota // e=0,f=0,g=0 values of iota are same in one line.
+	)
+	fmt.Printf("x = %v, y = %v, z = %v, w = %v\n", x, y, z, w)
+	fmt.Printf("v = %v\n", v)
+	fmt.Printf("e = %v, f = %v, g = %v\n", e, f, g)
+}
+
+// Functions and variables starting with a capital letter are public to other packages.
+// Everything else is private.
+func This_is_public()  {}
+func this_is_private() {}
+
+func set_default_values() {
+	// default values for the types.
+	const (
+		a int     = 0
+		b int8    = 0
+		c int32   = 0
+		d int64   = 0
+		e uint    = 0x0
+		f rune    = 0   // the actual type of rune is int32
+		g byte    = 0x0 // the actual type of byte is uint8
+		h float32 = 0   // length is 4 byte
+		i float64 = 0   //length is 8 byte
+		j bool    = false
+		k string  = ""
+	)
+}
+func show_arrays() {
+	fmt.Println("show_arrays()")
+	var arr [10]int // an array of type int
+	arr[0] = 42     // array is 0-based
+	arr[1] = 13     // assign value to element
+
+	a := [3]int{1, 2, 3} // define a int array with 3 elements
+
+	b := [10]int{1, 2, 3}
+	// define a int array with 10 elements,
+	// and first three are assigned, rest of them use default value 0.
+
+	c := [...]int{4, 5, 6} // use `…` replace with number of length, Go will calculate it for you.
+
+	// define a two-dimensional array with 2 elements, and each element has 4 elements.
+	doubleArray := [2][4]int{[4]int{1, 2, 3, 4}, [4]int{5, 6, 7, 8}}
+
+	// You can write about declaration in a shorter way.
+	easyArray := [2][4]int{{1, 2, 3, 4}, {5, 6, 7, 8}}
+
+	fmt.Println("arr =", arr)
+	fmt.Printf("The first element is %d\n", arr[0]) // get element value, it returns 42
+	fmt.Printf("The last element is %d\n", arr[9])
+	//it returns default value of 10th element in this array, which is 0 in this case.
+
+	fmt.Println("array a =", a)
+	fmt.Println("array b =", b)
+	fmt.Println("array c =", c)
+
+	fmt.Println("array doubleArray =", doubleArray)
+	fmt.Println("array easyArray =", easyArray)
+}
+func show_slices() {
+	fmt.Println("show_slices()")
+	// define a slice with 10 elements which types are byte
+	var ar = [10]byte{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'}
+
+	// define two slices with type []byte
+	var a, b []byte
+
+	// a points to elements from 3rd to 5th in array ar.
+	a = ar[2:5]
+	// now a has elements ar[2]、ar[3] and ar[4]
+
+	// b is another slice of array ar
+	b = ar[3:5]
+	// now b has elements ar[3] and ar[4]
+
+	// define an array
+	var array = [10]byte{'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j'}
+	// define two slices
+	var aSlice, bSlice []byte
+
+	// some convenient operations
+	aSlice = array[:3] // equals to aSlice = array[0:3] aSlice has elements a,b,c
+	aSlice = array[5:] // equals to aSlice = array[5:10] aSlice has elements f,g,h,i,j
+	aSlice = array[:]  // equals to aSlice = array[0:10] aSlice has all elements
+
+	// slice from slice
+	aSlice = array[3:7]  // aSlice has elements d,e,f,g，len=4，cap=7
+	bSlice = aSlice[1:3] // bSlice contains aSlice[1], aSlice[2], so it has elements e,f
+	bSlice = aSlice[:3]  // bSlice contains aSlice[0], aSlice[1], aSlice[2], so it has d,e,f
+	bSlice = aSlice[0:5] // slcie could be expanded in range of cap, now bSlice contains d,e,f,g,h
+	bSlice = aSlice[:]   // bSlice has same elements as aSlice does, which are d,e,f,g
+
+	fmt.Println("slice ar =", ar)
+	fmt.Println("slice a =", a)
+	fmt.Println("slice b =", b)
+	fmt.Println("array =", array)
+	fmt.Println("slice aSlice =", aSlice)
+	fmt.Println("slice bSlice =", bSlice)
+	fmt.Println("len(bSlice) =", len(bSlice))
+}
+func show_map() {
+	fmt.Println("show_map()")
+	// use string as key type, int as value type, and you have to use `make` initialize it.
+	var numbers map[string]int
+	// another way to define map
+	numbers = make(map[string]int)
+	numbers["one"] = 1 // assign value by key
+	numbers["ten"] = 10
+	numbers["three"] = 3
+
+	// Initialize a map
+	rating := map[string]float32{"C": 5, "Go": 4.5, "Python": 4.5, "C++": 2}
+
+	fmt.Println("map numbers =", numbers)
+	fmt.Println("The third number is: ", numbers["three"]) // get values
+	// It prints: The third number is: 3
+
+	// map has two return values. For second value, if the key doesn't exist，ok is false，true otherwise.
+	csharpRating, ok := rating["C#"]
+	if ok {
+		fmt.Println("C# is in the map and its rating is ", csharpRating)
+	} else {
+		fmt.Println("We have no rating associated with C# in the map")
+	}
+
+	delete(rating, "C") // delete element with key "c"
+	fmt.Printf("map rating = %#v\n", rating)
+}
+func main() {
+	show_multiple_assignments()
+	show_bool()
+	show_different_types()
+	show_strings()
+	show_string_manipulation()
+	show_errors()
+	show_iota()
+	set_default_values()
+	show_arrays()
+	show_slices()
+	show_map()
+}
--- a/fa/code/src/apps/ch.2.2/what_is_wrong_with_this/main.go
+++ b/fa/code/src/apps/ch.2.2/what_is_wrong_with_this/main.go
@@ -0,0 +1,8 @@
+// Example code for Chapter 2.2 from "Build Web Application with Golang"
+// Purpose: Try to fix this program.
+// From the console, type `go run main.go`
+package main
+
+func main() {
+    var i int
+}
--- a/fa/code/src/apps/ch.2.3/basic_functions/main.go
+++ b/fa/code/src/apps/ch.2.3/basic_functions/main.go
@@ -0,0 +1,26 @@
+// Example code for Chapter 2.3 from "Build Web Application with Golang"
+// Purpose: Creating a basic function
+package main
+
+import "fmt"
+
+// return greater value between a and b
+func max(a, b int) int {
+	if a > b {
+		return a
+	}
+	return b
+}
+
+func main() {
+	x := 3
+	y := 4
+	z := 5
+
+	max_xy := max(x, y) // call function max(x, y)
+	max_xz := max(x, z) // call function max(x, z)
+
+	fmt.Printf("max(%d, %d) = %d\n", x, y, max_xy)
+	fmt.Printf("max(%d, %d) = %d\n", x, z, max_xz)
+	fmt.Printf("max(%d, %d) = %d\n", y, z, max(y, z)) // call function here
+}
--- a/fa/code/src/apps/ch.2.3/hidden_print_methods/main.go
+++ b/fa/code/src/apps/ch.2.3/hidden_print_methods/main.go
@@ -0,0 +1,14 @@
+// As of Google go 1.1.2, `println()` and `print()` are hidden functions included from the runtime package.
+// However it's encouraged to use the print functions from the `fmt` package.
+package main
+
+import "fmt"
+
+func f() {
+	fmt.Println("First")
+	print("Second ")
+	println(" Third")
+}
+func main() {
+	f()
+}
--- a/fa/code/src/apps/ch.2.3/import_packages/main.go
+++ b/fa/code/src/apps/ch.2.3/import_packages/main.go
@@ -0,0 +1,26 @@
+// Example code for Chapter 2.3 from "Build Web Application with Golang"
+// Purpose: Shows different ways of importing a package.
+// Note: For the package `only_call_init`, we reference the path from the
+// base directory of `$GOPATH/src`. The reason being Golang discourage
+// the use of relative paths when import packages.
+// BAD: "./only_call_init"
+// GOOD: "apps/ch.2.3/import_packages/only_call_init"
+package main
+
+import (
+	// `_` will only call init() inside the package only_call_init
+	_ "apps/ch.2.3/import_packages/only_call_init"
+	f "fmt"         // import the package as `f`
+	. "math"        // makes the public methods and constants global
+	"mymath"        // custom package located at $GOPATH/src/
+	"os"            // normal import of a standard package
+	"text/template" // the package takes the name of last folder path, `template`
+)
+
+func main() {
+	f.Println("mymath.Sqrt(4) =", mymath.Sqrt(4))
+	f.Println("E =", E) // references math.E
+
+	t, _ := template.New("test").Parse("Pi^2 = {{.}}")
+	t.Execute(os.Stdout, Pow(Pi, 2))
+}
--- a/fa/code/src/apps/ch.2.3/import_packages/only_call_init/only_call_init.go
+++ b/fa/code/src/apps/ch.2.3/import_packages/only_call_init/only_call_init.go
@@ -0,0 +1,7 @@
+package only_call_init
+
+import "fmt"
+
+func init() {
+	fmt.Println("only_call_init.init() was called.")
+}
--- a/fa/code/src/apps/ch.2.3/main.go
+++ b/fa/code/src/apps/ch.2.3/main.go
@@ -0,0 +1,142 @@
+// Example code for Chapter 2.3 from "Build Web Application with Golang"
+// Purpose: Goes over if, else, switch conditions, loops and defer.
+package main
+
+import "fmt"
+
+func computedValue() int {
+	return 1
+}
+func show_if() {
+	fmt.Println("\n#show_if()")
+	x := computedValue()
+	integer := 23
+
+	fmt.Println("x =", x)
+	fmt.Println("integer =", integer)
+	if x > 10 {
+		fmt.Println("x is greater than 10")
+	} else {
+		fmt.Println("x is less than 10")
+	}
+
+	if integer == 3 {
+		fmt.Println("The integer is equal to 3")
+	} else if integer < 3 {
+		fmt.Println("The integer is less than 3")
+	} else {
+		fmt.Println("The integer is greater than 3")
+	}
+}
+func show_if_var() {
+	fmt.Println("\n#show_if_var()")
+	// initialize x, then check if x greater than
+	if x := computedValue(); x > 10 {
+		fmt.Println("x is greater than 10")
+	} else {
+		fmt.Println("x is less than 10")
+	}
+
+	// the following code will not compile, since `x` is only accessible with the if/else block
+	// fmt.Println(x)
+}
+func show_goto() {
+	fmt.Println("\n#show_goto()")
+	// The call to the label switches the goroutine it seems.
+	i := 0
+Here: // label ends with ":"
+	fmt.Println(i)
+	i++
+	if i < 10 {
+		goto Here // jump to label "Here"
+	}
+}
+func show_for_loop() {
+	fmt.Println("\n#show_for_loop()")
+	sum := 0
+	for index := 0; index < 10; index++ {
+		sum += index
+	}
+	fmt.Println("part 1, sum is equal to ", sum)
+
+	sum = 1
+	// The compiler will remove the `;` from the line below.
+	// for ; sum < 1000 ; {
+	for sum < 1000 {
+		sum += sum
+	}
+	fmt.Println("part 2, sum is equal to ", sum)
+
+	for index := 10; 0 < index; index-- {
+		if index == 5 {
+			break // or continue
+		}
+		fmt.Println(index)
+	}
+
+}
+func show_loop_through_map() {
+	fmt.Println("\n#show_loop_through_map()")
+	m := map[string]int{
+		"one":   1,
+		"two":   2,
+		"three": 3,
+	}
+	fmt.Println("map value = ", m)
+	for k, v := range m {
+		fmt.Println("map's key: ", k)
+		fmt.Println("map's value: ", v)
+	}
+}
+func show_switch() {
+	fmt.Println("\n#show_switch()")
+	i := 10
+	switch i {
+	case 1:
+		fmt.Println("i is equal to 1")
+	case 2, 3, 4:
+		fmt.Println("i is equal to 2, 3 or 4")
+	case 10:
+		fmt.Println("i is equal to 10")
+	default:
+		fmt.Println("All I know is that i is an integer")
+	}
+
+	integer := 6
+	fmt.Println("integer =", integer)
+	switch integer {
+	case 4:
+		fmt.Println("integer == 4")
+		fallthrough
+	case 5:
+		fmt.Println("integer <= 5")
+		fallthrough
+	case 6:
+		fmt.Println("integer <= 6")
+		fallthrough
+	case 7:
+		fmt.Println("integer <= 7")
+		fallthrough
+	case 8:
+		fmt.Println("integer <= 8")
+		fallthrough
+	default:
+		fmt.Println("default case")
+	}
+}
+func show_defer() {
+	fmt.Println("\nshow_defer()")
+	defer fmt.Println("(last defer)")
+	for i := 0; i < 5; i++ {
+		defer fmt.Printf("%d ", i)
+	}
+}
+func main() {
+	show_if()
+	show_if_var()
+	show_goto()
+	show_for_loop()
+	show_loop_through_map()
+	show_switch()
+	show_defer()
+}
--- a/fa/code/src/apps/ch.2.3/panic_and_recover/main.go
+++ b/fa/code/src/apps/ch.2.3/panic_and_recover/main.go
@@ -0,0 +1,31 @@
+// Example code for Chapter 2.3 from "Build Web Application with Golang"
+// Purpose: Showing how to use `panic()` and `recover()`
+package main
+
+import (
+	"fmt"
+	"os"
+)
+
+var user = os.Getenv("USER")
+
+func check_user() {
+	if user == "" {
+		panic("no value for $USER")
+	}
+	fmt.Println("Environment Variable `USER` =", user)
+}
+func throwsPanic(f func()) (b bool) {
+	defer func() {
+		if x := recover(); x != nil {
+			fmt.Println("Panic message =", x);
+			b = true
+		}
+	}()
+	f() // if f causes panic, it will recover
+	return
+}
+func main(){
+	didPanic := throwsPanic(check_user)
+	fmt.Println("didPanic =", didPanic)
+}
--- a/fa/code/src/apps/ch.2.3/pass_by_value_and_pointer/main.go
+++ b/fa/code/src/apps/ch.2.3/pass_by_value_and_pointer/main.go
@@ -0,0 +1,31 @@
+// Example code for Chapter 2.3 from "Build Web Application with Golang"
+// Purpose: Shows passing a variable by value and reference
+package main
+
+import "fmt"
+
+func add_by_value(a int) int {
+	a = a + 1
+	return a 
+}
+func add_by_reference(a *int) int {
+	*a = *a + 1 
+	return *a  
+}
+func show_add_by_value() {
+	x := 3
+	fmt.Println("x = ", x)
+	fmt.Println("add_by_value(x) =", add_by_value(x) )
+	fmt.Println("x = ", x)
+}
+func show_add_by_reference() {
+	x := 3
+	fmt.Println("x = ", x) 
+	// &x pass memory address of x
+	fmt.Println("add_by_reference(&x) =", add_by_reference(&x) )
+	fmt.Println("x = ", x) 
+}
+func main() {
+	show_add_by_value()
+	show_add_by_reference()
+}
--- a/fa/code/src/apps/ch.2.3/type_function/main.go
+++ b/fa/code/src/apps/ch.2.3/type_function/main.go
@@ -0,0 +1,44 @@
+// Example code for Chapter 2.3 from "Build Web Application with Golang"
+// Purpose: Shows how to define a function type
+package main
+
+import "fmt"
+
+type testInt func(int) bool // define a function type of variable
+
+func isOdd(integer int) bool {
+	if integer%2 == 0 {
+		return false
+	}
+	return true
+}
+
+func isEven(integer int) bool {
+	if integer%2 == 0 {
+		return true
+	}
+	return false
+}
+
+// pass the function `f` as an argument to another function
+
+func filter(slice []int, f testInt) []int {
+	var result []int
+	for _, value := range slice {
+		if f(value) {
+			result = append(result, value)
+		}
+	}
+	return result
+}
+func init() {
+	fmt.Println("\n#init() was called.")
+}
+func main() {
+	slice := []int{1, 2, 3, 4, 5, 7}
+	fmt.Println("slice = ", slice)
+	odd := filter(slice, isOdd) // use function as values
+	fmt.Println("Odd elements of slice are: ", odd)
+	even := filter(slice, isEven)
+	fmt.Println("Even elements of slice are: ", even)
+}
--- a/fa/code/src/apps/ch.2.3/variadic_functions/main.go
+++ b/fa/code/src/apps/ch.2.3/variadic_functions/main.go
@@ -0,0 +1,20 @@
+// Example code for Chapter 2.3 from "Build Web Application with Golang"
+// Purpose: Shows how to return multiple values from a function
+package main
+
+import "fmt"
+
+// return results of A + B and A * B
+func SumAndProduct(A, B int) (int, int) {
+	return A + B, A * B
+}
+
+func main() {
+	x := 3
+	y := 4
+
+	xPLUSy, xTIMESy := SumAndProduct(x, y)
+
+	fmt.Printf("%d + %d = %d\n", x, y, xPLUSy)
+	fmt.Printf("%d * %d = %d\n", x, y, xTIMESy)
+}
--- a/fa/code/src/apps/ch.2.4/compare_age/main.go
+++ b/fa/code/src/apps/ch.2.4/compare_age/main.go
@@ -0,0 +1,43 @@
+// Example code for Chapter 2.4 from "Build Web Application with Golang"
+// Purpose: Shows you how to pass and use structs.
+package main
+
+import "fmt"
+
+// define a new type
+type person struct {
+	name string
+	age  int
+}
+
+// compare age of two people, return the older person and differences of age
+// struct is passed by value
+func Older(p1, p2 person) (person, int) {
+	if p1.age > p2.age {
+		return p1, p1.age - p2.age
+	}
+	return p2, p2.age - p1.age
+}
+
+func main() {
+	var tom person
+
+	// initialization
+	tom.name, tom.age = "Tom", 18
+
+	// initialize two values by format "field:value"
+	bob := person{age: 25, name: "Bob"}
+
+	// initialize two values with order
+	paul := person{"Paul", 43}
+
+	tb_Older, tb_diff := Older(tom, bob)
+	tp_Older, tp_diff := Older(tom, paul)
+	bp_Older, bp_diff := Older(bob, paul)
+
+	fmt.Printf("Of %s and %s, %s is older by %d years\n", tom.name, bob.name, tb_Older.name, tb_diff)
+
+	fmt.Printf("Of %s and %s, %s is older by %d years\n", tom.name, paul.name, tp_Older.name, tp_diff)
+
+	fmt.Printf("Of %s and %s, %s is older by %d years\n", bob.name, paul.name, bp_Older.name, bp_diff)
+}
--- a/fa/code/src/apps/ch.2.4/embedded_structs/main.go
+++ b/fa/code/src/apps/ch.2.4/embedded_structs/main.go
@@ -0,0 +1,39 @@
+// Example code for Chapter 2.4 from "Build Web Application with Golang"
+// Purpose: Example of embedded fields
+package main
+
+import "fmt"
+
+type Human struct {
+	name   string
+	age    int
+	weight int
+}
+
+type Student struct {
+	Human      // anonymous field, it means Student struct includes all fields that Human has.
+	speciality string
+}
+
+func main() {
+	// initialize a student
+	mark := Student{Human{"Mark", 25, 120}, "Computer Science"}
+
+	// access fields
+	fmt.Println("His name is ", mark.name)
+	fmt.Println("His age is ", mark.age)
+	fmt.Println("His weight is ", mark.weight)
+	fmt.Println("His speciality is ", mark.speciality)
+	// modify notes
+	mark.speciality = "AI"
+	fmt.Println("Mark changed his speciality")
+	fmt.Println("His speciality is ", mark.speciality)
+	// modify age
+	fmt.Println("Mark become old")
+	mark.age = 46
+	fmt.Println("His age is", mark.age)
+	// modify weight
+	fmt.Println("Mark is not an athlete any more")
+	mark.weight += 60
+	fmt.Println("His weight is", mark.weight)
+}
--- a/fa/code/src/apps/ch.2.4/embedded_structs2/main.go
+++ b/fa/code/src/apps/ch.2.4/embedded_structs2/main.go
@@ -0,0 +1,39 @@
+// Example code for Chapter 2.4 from "Build Web Application with Golang"
+// Purpose: Another example of embedded fields
+package main
+
+import "fmt"
+
+type Skills []string
+
+type Human struct {
+	name   string
+	age    int
+	weight int
+}
+
+type Student struct {
+	Human      // struct as embedded field
+	Skills     // string slice as embedded field
+	int        // built-in type as embedded field
+	speciality string
+}
+
+func main() {
+	// initialize Student Jane
+	jane := Student{Human: Human{"Jane", 35, 100}, speciality: "Biology"}
+	// access fields
+	fmt.Println("Her name is ", jane.name)
+	fmt.Println("Her age is ", jane.age)
+	fmt.Println("Her weight is ", jane.weight)
+	fmt.Println("Her speciality is ", jane.speciality)
+	// modify value of skill field
+	jane.Skills = []string{"anatomy"}
+	fmt.Println("Her skills are ", jane.Skills)
+	fmt.Println("She acquired two new ones ")
+	jane.Skills = append(jane.Skills, "physics", "golang")
+	fmt.Println("Her skills now are ", jane.Skills)
+	// modify embedded field
+	jane.int = 3
+	fmt.Println("Her preferred number is", jane.int)
+}
--- a/fa/code/src/apps/ch.2.4/embedded_structs_with_name_conflict/main.go
+++ b/fa/code/src/apps/ch.2.4/embedded_structs_with_name_conflict/main.go
@@ -0,0 +1,24 @@
+// Example code for Chapter 2.4 from "Build Web Application with Golang"
+// Purpose: Shows a name conflict with a embedded field
+package main
+
+import "fmt"
+
+type Human struct {
+	name  string
+	age   int
+	phone string // Human has phone field
+}
+
+type Employee struct {
+	Human      // embedded field Human
+	speciality string
+	phone      string // phone in employee
+}
+
+func main() {
+	Bob := Employee{Human{"Bob", 34, "777-444-XXXX"}, "Designer", "333-222"}
+	fmt.Println("Bob's work phone is:", Bob.phone)
+	// access phone field in Human
+	fmt.Println("Bob's personal phone is:", Bob.Human.phone)
+}
--- a/fa/code/src/apps/ch.2.4/main.go
+++ b/fa/code/src/apps/ch.2.4/main.go
@@ -0,0 +1,39 @@
+// Example code for Chapter 2.4 from "Build Web Application with Golang"
+// Purpose: Shows different ways of creating a struct
+package main
+
+import "fmt"
+
+func show_basic_struct() {
+	fmt.Println("\nshow_basic_struct()")
+	type person struct {
+		name string
+		age  int
+	}
+
+	var P person // p is person type
+
+	P.name = "Astaxie"                              // assign "Astaxie" to the filed 'name' of p
+	P.age = 25                                      // assign 25 to field 'age' of p
+	fmt.Printf("The person's name is %s\n", P.name) // access field 'name' of p
+
+	tom := person{"Tom", 25}
+
+	bob := person{age: 24, name: "Bob"}
+
+	fmt.Printf("tom = %+v\n", tom)
+	fmt.Printf("bob = %#v\n", bob)
+}
+func show_anonymous_struct() {
+	fmt.Println("\nshow_anonymous_struct()")
+	fmt.Printf("Anonymous struct = %#v\n", struct {
+		name  string
+		count int
+	}{
+		"counter", 1,
+	})
+}
+func main() {
+	show_basic_struct()
+	show_anonymous_struct()
+}
--- a/fa/code/src/apps/ch.2.5/attach_methods_to_struct/main.go
+++ b/fa/code/src/apps/ch.2.5/attach_methods_to_struct/main.go
@@ -0,0 +1,36 @@
+// Example code from Chapter 2.5
+// Attach method to struct.
+package main
+
+import (
+	"fmt"
+	"math"
+)
+
+type Rectangle struct {
+	width, height float64
+}
+
+type Circle struct {
+	radius float64
+}
+
+func (r Rectangle) area() float64 {
+	return r.width * r.height
+}
+
+func (c Circle) area() float64 {
+	return c.radius * c.radius * math.Pi
+}
+
+func main() {
+	r1 := Rectangle{12, 2}
+	r2 := Rectangle{9, 4}
+	c1 := Circle{10}
+	c2 := Circle{25}
+
+	fmt.Println("Area of r1 is: ", r1.area())
+	fmt.Println("Area of r2 is: ", r2.area())
+	fmt.Println("Area of c1 is: ", c1.area())
+	fmt.Println("Area of c2 is: ", c2.area())
+}
--- a/fa/code/src/apps/ch.2.5/box_example/main.go
+++ b/fa/code/src/apps/ch.2.5/box_example/main.go
@@ -0,0 +1,73 @@
+package main
+
+import "fmt"
+
+const (
+	WHITE = iota
+	BLACK
+	BLUE
+	RED
+	YELLOW
+)
+
+type Color byte
+
+type Box struct {
+	width, height, depth float64
+	color                Color
+}
+
+type BoxList []Box //a slice of boxes
+
+func (b Box) Volume() float64 {
+	return b.width * b.height * b.depth
+}
+
+func (b *Box) SetColor(c Color) {
+	b.color = c
+}
+
+func (bl BoxList) BiggestsColor() Color {
+	v := 0.00
+	k := Color(WHITE)
+	for _, b := range bl {
+		if b.Volume() > v {
+			v = b.Volume()
+			k = b.color
+		}
+	}
+	return k
+}
+
+func (bl BoxList) PaintItBlack() {
+	for i, _ := range bl {
+		bl[i].SetColor(BLACK)
+	}
+}
+
+func (c Color) String() string {
+	strings := []string{"WHITE", "BLACK", "BLUE", "RED", "YELLOW"}
+	return strings[c]
+}
+
+func main() {
+	boxes := BoxList{
+		Box{4, 4, 4, RED},
+		Box{10, 10, 1, YELLOW},
+		Box{1, 1, 20, BLACK},
+		Box{10, 10, 1, BLUE},
+		Box{10, 30, 1, WHITE},
+		Box{20, 20, 20, YELLOW},
+	}
+
+	fmt.Printf("We have %d boxes in our set\n", len(boxes))
+	fmt.Println("The volume of the first one is", boxes[0].Volume(), "cm³")
+	fmt.Println("The color of the last one is", boxes[len(boxes)-1].color.String())
+	fmt.Println("The biggest one is", boxes.BiggestsColor().String())
+
+	fmt.Println("Let's paint them all black")
+	boxes.PaintItBlack()
+	fmt.Println("The color of the second one is", boxes[1].color.String())
+
+	fmt.Println("Obviously, now, the biggest one is", boxes.BiggestsColor().String())
+}
--- a/fa/code/src/apps/ch.2.5/embedded_method/main.go
+++ b/fa/code/src/apps/ch.2.5/embedded_method/main.go
@@ -0,0 +1,31 @@
+package main
+import "fmt"
+
+type Human struct {
+    name string
+    age int
+    phone string
+}
+
+type Student struct {
+    Human // anonymous field
+    school string
+}
+
+type Employee struct {
+    Human 
+    company string
+}
+
+// define a method in Human
+func (h *Human) SayHi() {
+    fmt.Printf("Hi, I am %s you can call me on %s\n", h.name, h.phone)
+}
+
+func main() {
+    mark := Student{Human{"Mark", 25, "222-222-YYYY"}, "MIT"}
+    sam := Employee{Human{"Sam", 45, "111-888-XXXX"}, "Golang Inc"}
+
+    mark.SayHi()
+    sam.SayHi()
+}
--- a/fa/code/src/apps/ch.2.5/method_overload/main.go
+++ b/fa/code/src/apps/ch.2.5/method_overload/main.go
@@ -0,0 +1,36 @@
+package main
+
+import "fmt"
+
+type Human struct {
+	name  string
+	age   int
+	phone string
+}
+
+type Student struct {
+	Human
+	school string
+}
+
+type Employee struct {
+	Human
+	company string
+}
+
+func (h *Human) SayHi() {
+	fmt.Printf("Hi, I am %s you can call me on %s\n", h.name, h.phone)
+}
+
+func (e *Employee) SayHi() {
+	fmt.Printf("Hi, I am %s, I work at %s. Call me on %s\n", e.name,
+		e.company, e.phone) //Yes you can split into 2 lines here.
+}
+
+func main() {
+	mark := Student{Human{"Mark", 25, "222-222-YYYY"}, "MIT"}
+	sam := Employee{Human{"Sam", 45, "111-888-XXXX"}, "Golang Inc"}
+
+	mark.SayHi()
+	sam.SayHi()
+}
--- a/fa/code/src/apps/ch.2.5/pass_struct_to_method/main.go
+++ b/fa/code/src/apps/ch.2.5/pass_struct_to_method/main.go
@@ -0,0 +1,18 @@
+package main
+
+import "fmt"
+
+type Rectangle struct {
+	width, height float64
+}
+
+func area(r Rectangle) float64 {
+	return r.width * r.height
+}
+
+func main() {
+	r1 := Rectangle{12, 2}
+	r2 := Rectangle{9, 4}
+	fmt.Println("Area of r1 is: ", area(r1))
+	fmt.Println("Area of r2 is: ", area(r2))
+}
--- a/fa/code/src/apps/ch.2.6/interface/main.go
+++ b/fa/code/src/apps/ch.2.6/interface/main.go
@@ -0,0 +1,71 @@
+package main
+import "fmt"
+
+type Human struct {
+    name string
+    age int
+    phone string
+}
+
+type Student struct {
+    Human 
+    school string
+    loan float32
+}
+
+type Employee struct {
+    Human 
+    company string
+    money float32
+}
+
+func (h Human) SayHi() {
+    fmt.Printf("Hi, I am %s you can call me on %s\n", h.name, h.phone)
+}
+
+func (h Human) Sing(lyrics string) {
+    fmt.Println("La la la la...", lyrics)
+}
+
+func (e Employee) SayHi() {
+    fmt.Printf("Hi, I am %s, I work at %s. Call me on %s\n", e.name,
+        e.company, e.phone) //Yes you can split into 2 lines here.
+}
+
+// Interface Men implemented by Human, Student and Employee 
+type Men interface {
+    SayHi()
+    Sing(lyrics string)
+}
+
+func main() {
+    mike := Student{Human{"Mike", 25, "222-222-XXX"}, "MIT", 0.00}
+    paul := Student{Human{"Paul", 26, "111-222-XXX"}, "Harvard", 100}
+    sam := Employee{Human{"Sam", 36, "444-222-XXX"}, "Golang Inc.", 1000}
+    Tom := Employee{Human{"Sam", 36, "444-222-XXX"}, "Things Ltd.", 5000}
+
+    // define interface i
+    var i Men
+
+    //i can store Student
+    i = mike
+    fmt.Println("This is Mike, a Student:")
+    i.SayHi()
+    i.Sing("November rain")
+
+    //i can store Employee
+    i = Tom
+    fmt.Println("This is Tom, an Employee:")
+    i.SayHi()
+    i.Sing("Born to be wild")
+
+    // slice of Men
+    fmt.Println("Let's use a slice of Men and see what happens")
+    x := make([]Men, 3)
+    // these three elements are different types but they all implemented interface Men
+    x[0], x[1], x[2] = paul, sam, mike
+
+    for _, value := range x{
+        value.SayHi()
+    }
+}
--- a/fa/code/src/apps/ch.2.6/reflection/main.go
+++ b/fa/code/src/apps/ch.2.6/reflection/main.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"fmt"
+	"reflect"
+)
+
+func show_interface_none() {
+	fmt.Println("\nshow_interface_none()")
+	var a interface{}
+	a = "string"
+	a = 1
+	a = false
+	fmt.Println("a =", a)
+}
+func show_reflection() {
+	fmt.Println("\nshow_reflection()")
+	var x float64 = 3.4
+	v := reflect.ValueOf(x)
+	fmt.Println("type:", v.Type())
+	fmt.Println("kind is float64:", v.Kind() == reflect.Float64)
+	fmt.Println("value:", v.Float())
+	
+	p := reflect.ValueOf(&x)
+	newX := p.Elem()
+	newX.SetFloat(7.1)
+	fmt.Println("newX =", newX)
+	fmt.Println("newX float64() value:", newX.Float())
+}
+func main() {
+	show_interface_none()
+	show_reflection()
+}
--- a/fa/code/src/apps/ch.2.6/stringer_interface/main.go
+++ b/fa/code/src/apps/ch.2.6/stringer_interface/main.go
@@ -0,0 +1,22 @@
+package main
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type Human struct {
+	name  string
+	age   int
+	phone string
+}
+
+// Human implemented fmt.Stringer
+func (h Human) String() string {
+	return "Name:" + h.name + ", Age:" + strconv.Itoa(h.age) + " years, Contact:" + h.phone
+}
+
+func main() {
+	Bob := Human{"Bob", 39, "000-7777-XXX"}
+	fmt.Println("This Human is : ", Bob)
+}
--- a/fa/code/src/apps/ch.2.6/switch_type_check/main.go
+++ b/fa/code/src/apps/ch.2.6/switch_type_check/main.go
@@ -0,0 +1,38 @@
+package main
+
+import (
+    "fmt"
+    "strconv"
+)
+
+type Element interface{}
+type List []Element
+
+type Person struct {
+    name string
+    age  int
+}
+
+func (p Person) String() string {
+    return "(name: " + p.name + " - age: " + strconv.Itoa(p.age) + " years)"
+}
+
+func main() {
+    list := make(List, 3)
+    list[0] = 1       //an int
+    list[1] = "Hello" //a string
+    list[2] = Person{"Dennis", 70}
+
+    for index, element := range list {
+        switch value := element.(type) {
+        case int:
+            fmt.Printf("list[%d] is an int and its value is %d\n", index, value)
+        case string:
+            fmt.Printf("list[%d] is a string and its value is %s\n", index, value)
+        case Person:
+            fmt.Printf("list[%d] is a Person and its value is %s\n", index, value)
+        default:
+            fmt.Println("list[%d] is of a different type", index)
+        }
+    }
+}
--- a/fa/code/src/apps/ch.2.6/type_check/main.go
+++ b/fa/code/src/apps/ch.2.6/type_check/main.go
@@ -0,0 +1,37 @@
+package main
+
+import (
+    "fmt"
+    "strconv"
+)
+
+type Element interface{}
+type List []Element
+
+type Person struct {
+    name string
+    age  int
+}
+
+func (p Person) String() string {
+    return "(name: " + p.name + " - age:    " + strconv.Itoa(p.age) + " years)"
+}
+
+func main() {
+    list := make(List, 3)
+    list[0] = 1       // an int
+    list[1] = "Hello" // a string
+    list[2] = Person{"Dennis", 70}
+
+    for index, element := range list {
+        if value, ok := element.(int); ok {
+            fmt.Printf("list[%d] is an int and its value is %d\n", index, value)
+        } else if value, ok := element.(string); ok {
+            fmt.Printf("list[%d] is a string and its value is %s\n", index, value)
+        } else if value, ok := element.(Person); ok {
+            fmt.Printf("list[%d] is a Person and its value is %s\n", index, value)
+        } else {
+            fmt.Println("list[%d] is of a different type", index)
+        }
+    }
+}
--- a/fa/code/src/apps/ch.2.7/buffered_channel/main.go
+++ b/fa/code/src/apps/ch.2.7/buffered_channel/main.go
@@ -0,0 +1,13 @@
+// Example code for Chapter 2.7 from "Build Web Application with Golang"
+// Purpose: Shows how to use a buffered channel
+package main
+
+import "fmt"
+
+func main() {
+	c := make(chan int, 2) // change 2 to 1 will have runtime error, but 3 is fine
+	c <- 1
+	c <- 2
+	fmt.Println(<-c)
+	fmt.Println(<-c)
+}
--- a/fa/code/src/apps/ch.2.7/goroutine/main.go
+++ b/fa/code/src/apps/ch.2.7/goroutine/main.go
@@ -0,0 +1,20 @@
+// Example code for Chapter 2.7 from "Build Web Application with Golang"
+// Purpose: Shows how to launch a simple gorountine
+package main
+
+import (
+	"fmt"
+	"runtime"
+)
+
+func say(s string) {
+	for i := 0; i < 5; i++ {
+		runtime.Gosched()
+		fmt.Println(s)
+	}
+}
+
+func main() {
+	go say("world") // create a new goroutine
+	say("hello")    // current goroutine
+}
--- a/fa/code/src/apps/ch.2.7/range_and_close_channel/main.go
+++ b/fa/code/src/apps/ch.2.7/range_and_close_channel/main.go
@@ -0,0 +1,24 @@
+// Example code for Chapter 2.7 from "Build Web Application with Golang"
+// Purpose: Shows how to close and interate through a channel
+package main
+
+import (
+	"fmt"
+)
+
+func fibonacci(n int, c chan int) {
+	x, y := 1, 1
+	for i := 0; i < n; i++ {
+		c <- x
+		x, y = y, x+y
+	}
+	close(c)
+}
+
+func main() {
+	c := make(chan int, 10)
+	go fibonacci(cap(c), c)
+	for i := range c {
+		fmt.Println(i)
+	}
+}
--- a/fa/code/src/apps/ch.2.7/select_channel/main.go
+++ b/fa/code/src/apps/ch.2.7/select_channel/main.go
@@ -0,0 +1,30 @@
+// Example code for Chapter 2.7 from "Build Web Application with Golang"
+// Purpose: Shows how to use `select`
+package main
+
+import "fmt"
+
+func fibonacci(c, quit chan int) {
+	x, y := 1, 1
+	for {
+		select {
+		case c <- x:
+			x, y = y, x+y
+		case <-quit:
+			fmt.Println("quit")
+			return
+		}
+	}
+}
+
+func main() {
+	c := make(chan int)
+	quit := make(chan int)
+	go func() {
+		for i := 0; i < 10; i++ {
+			fmt.Println(<-c)
+		}
+		quit <- 0
+	}()
+	fibonacci(c, quit)
+}
--- a/fa/code/src/apps/ch.2.7/timeout/main.go
+++ b/fa/code/src/apps/ch.2.7/timeout/main.go
@@ -0,0 +1,27 @@
+// Example code for Chapter 2.7 from "Build Web Application with Golang"
+// Purpose: Shows how to create and use a timeout
+package main
+
+import (
+	"fmt"
+	"time"
+)
+
+
+func main() {
+	c := make(chan int)
+	o := make(chan bool)
+	go func() {
+		for {
+			select {
+			case v := <-c:
+				fmt.Println(v)
+			case <-time.After(5 * time.Second):
+				fmt.Println("timeout")
+				o <- true
+				break
+			}
+		}
+	}()
+	<-o
+}
--- a/fa/code/src/apps/ch.2.7/unbuffered_channel/main.go
+++ b/fa/code/src/apps/ch.2.7/unbuffered_channel/main.go
@@ -0,0 +1,24 @@
+// Example code for Chapter 2.7 from "Build Web Application with Golang"
+// Purpose: Shows how to create and use a unbuffered channel
+package main
+
+import "fmt"
+
+func sum(a []int, c chan int) {
+	total := 0
+	for _, v := range a {
+		total += v
+	}
+	c <- total // send total to c
+}
+
+func main() {
+	a := []int{7, 2, 8, -9, 4, 0}
+
+	c := make(chan int)
+	go sum(a[:len(a)/2], c)
+	go sum(a[len(a)/2:], c)
+	x, y := <-c, <-c // receive from c
+
+	fmt.Println(x, y, x+y)
+}
--- a/fa/code/src/apps/ch.3.2/main.go
+++ b/fa/code/src/apps/ch.3.2/main.go
@@ -0,0 +1,31 @@
+// Example code for Chapter 3.2 from "Build Web Application with Golang"
+// Purpose: Shows how to acces the form values from the request
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/http"
+	"strings"
+)
+
+func sayhelloName(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()       // parse arguments, you have to call this by yourself
+	fmt.Println(r.Form) // print form information in server side
+	fmt.Println("path", r.URL.Path)
+	fmt.Println("scheme", r.URL.Scheme)
+	fmt.Println(r.Form["url_long"])
+	for k, v := range r.Form {
+		fmt.Println("key:", k)
+		fmt.Println("val:", strings.Join(v, ""))
+	}
+	fmt.Fprintf(w, "Hello astaxie!") // send data to client side
+}
+
+func main() {
+	http.HandleFunc("/", sayhelloName)       // set router
+	err := http.ListenAndServe(":9090", nil) // set listen port
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}
--- a/fa/code/src/apps/ch.3.4/main.go
+++ b/fa/code/src/apps/ch.3.4/main.go
@@ -0,0 +1,30 @@
+// Example code for Chapter 3.4 from "Build Web Application with Golang"
+// Purpose: Shows how to create a handler for `http.ListenAndServe()`
+// Run `go run main.go` then access `http://localhost:9090`
+package main
+
+import (
+	"fmt"
+	"net/http"
+)
+
+type MyMux struct {
+}
+
+func (p *MyMux) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path == "/" {
+		sayhelloName(w, r)
+		return
+	}
+	http.NotFound(w, r)
+	return
+}
+
+func sayhelloName(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "Hello myroute!")
+}
+
+func main() {
+	mux := &MyMux{}
+	http.ListenAndServe(":9090", mux)
+}
--- a/fa/code/src/apps/ch.4.1/login.gtpl
+++ b/fa/code/src/apps/ch.4.1/login.gtpl
@@ -0,0 +1,12 @@
+<html>
+<head>
+<title></title>
+</head>
+<body>
+<form action="/login" method="post">
+    Username:<input type="text" name="username">
+    Password:<input type="password" name="password">
+    <input type="submit" value="Login">
+</form>
+</body>
+</html>
--- a/fa/code/src/apps/ch.4.1/main.go
+++ b/fa/code/src/apps/ch.4.1/main.go
@@ -0,0 +1,48 @@
+// Example code for Chapter 4.1 from "Build Web Application with Golang"
+// Purpose: Shows how to create a simple login using a template
+// Run: `go run main.go`, then access `http://localhost:9090` and `http://localhost:9090/login`
+package main
+
+import (
+	"fmt"
+	"html/template"
+	"log"
+	"net/http"
+	"strings"
+)
+
+func sayhelloName(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()  //Parse url parameters passed, then parse the response packet for the POST body (request body)
+	// attention: If you do not call ParseForm method, the following data can not be obtained form
+	fmt.Println(r.Form) // print information on server side.
+	fmt.Println("path", r.URL.Path)
+	fmt.Println("scheme", r.URL.Scheme)
+	fmt.Println(r.Form["url_long"])
+	for k, v := range r.Form {
+		fmt.Println("key:", k)
+		fmt.Println("val:", strings.Join(v, ""))
+	}
+	fmt.Fprintf(w, "Hello astaxie!") // write data to response
+}
+
+func login(w http.ResponseWriter, r *http.Request) {
+	fmt.Println("method:", r.Method) //get request method
+	if r.Method == "GET" {
+		t, _ := template.ParseFiles("login.gtpl")
+		t.Execute(w, nil)
+	} else {
+		r.ParseForm()
+		// logic part of log in
+		fmt.Println("username:", r.Form["username"])
+		fmt.Println("password:", r.Form["password"])
+	}
+}
+	
+func main() {
+	http.HandleFunc("/", sayhelloName) // setting router rule
+	http.HandleFunc("/login", login)
+	err := http.ListenAndServe(":9090", nil) // setting listening port
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}
--- a/fa/code/src/apps/ch.4.2/main.go
+++ b/fa/code/src/apps/ch.4.2/main.go
@@ -0,0 +1,59 @@
+// Example code for Chapter 4.2 from "Build Web Application with Golang"
+// Purpose: Shows how to perform server-side validation of user input from a form.
+// Also shows to use multiple template files with predefined template names.
+// Run `go run main.go` and then access http://localhost:9090
+package main
+
+import (
+	"apps/ch.4.2/validator"
+	"html/template"
+	"log"
+	"net/http"
+)
+
+const (
+	PORT     = "9090"
+	HOST_URL = "http://localhost:" + PORT
+)
+
+var t *template.Template
+
+type Links struct {
+	BadLinks [][2]string
+}
+
+// invalid links to display for testing.
+var links Links
+
+func index(w http.ResponseWriter, r *http.Request) {
+	http.Redirect(w, r, HOST_URL+"/profile", http.StatusTemporaryRedirect)
+}
+func profileHandler(w http.ResponseWriter, r *http.Request) {
+	t.ExecuteTemplate(w, "profile", links)
+}
+func checkProfile(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()
+	p := validator.ProfilePage{&r.Form}
+	t.ExecuteTemplate(w, "submission", p.GetErrors())
+}
+
+// This function is called before main()
+func init() {
+	// Note: we can reference the loaded templates by their defined name inside the template files.
+	t = template.Must(template.ParseFiles("profile.gtpl", "submission.gtpl"))
+
+	list := make([][2]string, 2)
+	list[0] = [2]string{HOST_URL + "/checkprofile", "No data"}
+	list[1] = [2]string{HOST_URL + "/checkprofile?age=1&gender=guy&shirtsize=big", "Invalid options"}
+	links = Links{list}
+}
+func main() {
+	http.HandleFunc("/", index)
+	http.HandleFunc("/profile", profileHandler)
+	http.HandleFunc("/checkprofile", checkProfile)
+
+	err := http.ListenAndServe(":"+PORT, nil) // setting listening port
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}
--- a/fa/code/src/apps/ch.4.2/profile.gtpl
+++ b/fa/code/src/apps/ch.4.2/profile.gtpl
@@ -0,0 +1,89 @@
+{{define "profile"}}<!DOCTYPE html>
+<html>
+	<style>
+	.row{
+		display: table-row;
+	}
+	.cell{
+		display: table-cell;
+	}
+	.required{
+		color: red
+	}
+	</style>
+	<body>				
+		<h2>Profile Setup:</h2>
+		<form action="/checkprofile">
+				<div class="row">
+					<div class="cell"><span class="required">*</span>User Name:</div>
+					<div class="cell"><input type="text" name="username" id="username" required/></div>
+				</div>
+				<div class="row">
+					<div class="cell"><span class="required">*</span>Age:</div>
+					<div class="cell"><input type="number" min="13" max="130" name="age" id="age" size="3" required/></div>
+				</div>
+				<div class="row">
+					<div class="cell"><span class="required">*</span>Email:</div>
+					<div class="cell"><input type="email" name="email" id="email" placeholder="john@example.com" required/></div>
+				</div>
+				<div class="row">
+					<div class="cell"><span class="required">*</span>Birth day:</div>
+					<div class="cell">
+						<input type="date" name="birthday" id="birthday" placeholder="MM/DD/YYYY" required/>
+					</div>
+				</div>
+				<div class="row">
+					<div class="cell">Gender:</div>
+					<div class="cell">
+						<label for="gender_male">
+							Male: <input type="radio" name="gender" value="m" id="gender_male"/>
+						</label>
+						<label for="gender_female">
+							Female: <input type="radio" name="gender" value="f" id="gender_female"/>
+						</label>
+						<label for="gender_na">
+							N/A: <input type="radio" name="gender" value="na" id="gender_na"/>
+						</label>
+					</div>
+				</div>
+				<div class="row">
+					<div class="cell">Siblings:</div>
+					<div class="cell">
+						<label for="sibling_male">
+							Brother: <input type="checkbox" name="sibling" value="m" id="sibling_male"/>
+						</label>
+						<label for="sibling_female">
+							Sister: <input type="checkbox" name="sibling" value="f" id="sibling_female"/>
+						</label>
+					</div>
+				</div>
+			<div class="row">
+				<div class="cell">Shirt Size:</div>
+				<div class="cell">
+					<select id="shirt_size" >
+						<option></option>
+						<option value="s">Small</option>
+						<option value="m">Medium</option>
+						<option value="l">Large</option>
+						<option value="xl">X-Large</option>
+						<option value="xxl">XX-Large</option>
+					</select>
+				</div>
+			</div>
+			<div class="row">
+				<div class="cell">Chinese Name:</div>
+				<div class="cell"><input type="text" name="chineseName" id="chineseName"/></div>
+			</div>
+			<br/>
+			<span class="required">*</span>Required
+			<br/>
+			<input type="submit" value="Submit" id="submitBtn"/>
+		</form>
+		<h2>Invalid submissions</h2>
+		<ol>{{range .BadLinks}}
+		<li><a href="{{index . 0}}">{{index . 1}}</a></li>
+		{{end}}
+		</ol>
+	</body>
+</html>
+{{end}}
--- a/fa/code/src/apps/ch.4.2/submission.gtpl
+++ b/fa/code/src/apps/ch.4.2/submission.gtpl
@@ -0,0 +1,16 @@
+{{define "submission"}}<!DOCTYPE html>
+<html>
+	<body>
+		{{if .Errors}}
+		<h2>Errors:</h2>
+			<ol>
+				{{range .Errors}}	
+				<li>{{.}}</li>
+				{{end}}
+			</ol>	
+	{{else}}
+	Profile successfully submitted.
+	{{end}}
+	</body>
+</html>
+{{end}}
--- a/fa/code/src/apps/ch.4.2/validator/main.go
+++ b/fa/code/src/apps/ch.4.2/validator/main.go
@@ -0,0 +1,175 @@
+// This file contains all the validators to validate the profile page.
+package validator
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type ProfilePage struct {
+	Form *url.Values
+}
+type Errors struct {
+	Errors []error
+}
+
+// Goes through the form object and validates each element.
+// Attachs an error to the output if validation fails.
+func (p *ProfilePage) GetErrors() Errors {
+	errs := make([]error, 0, 10)
+	if *p.Form == nil || len(*p.Form) < 1 {
+		errs = append(errs, errors.New("No data was received. Please submit from the profile page."))
+	}
+	for name, val := range *p.Form {
+		if fn, ok := stringValidator[name]; ok {
+			if err := fn(strings.Join(val, "")); err != nil {
+				errs = append(errs, err)
+			}
+		} else {
+			if fn, ok := stringsValidator[name]; ok {
+				if err := fn(val); err != nil {
+					errs = append(errs, err)
+				}
+			}
+		}
+	}
+	return Errors{errs}
+}
+
+const (
+	// Used for parsing the time
+	mmddyyyyForm = "01/02/2006" // we want the date sent in this format
+	yyyymmddForm = "2006-01-02" // However, HTML5 pages send the date in this format
+)
+
+var stringValidator map[string]func(string) error = map[string]func(string) error{
+	// parameter name : validator reference
+	"age":         checkAge,
+	"birthday":    checkDate,
+	"chineseName": checkChineseName,
+	"email":       checkEmail,
+	"gender":      checkGender,
+	"shirtsize":   checkShirtSize,
+	"username":    checkUsername,
+}
+var stringsValidator map[string]func([]string) error = map[string]func([]string) error{
+	// parameter name : validator reference
+	"sibling": checkSibling,
+}
+
+// Returns true if slices have a common element
+func doSlicesIntersect(s1, s2 []string) bool {
+	if s1 == nil || s2 == nil {
+		return false
+	}
+	for _, str := range s1 {
+		if isElementInSlice(str, s2) {
+			return true
+		}
+	}
+	return false
+}
+func isElementInSlice(str string, sl []string) bool {
+	if sl == nil || str == "" {
+		return false
+	}
+	for _, v := range sl {
+		if v == str {
+			return true
+		}
+	}
+	return false
+}
+
+// Checks if all the characters are chinese characters. Won't check if empty.'
+func checkChineseName(str string) error {
+	if str != "" {
+		if m, _ := regexp.MatchString("^[\\x{4e00}-\\x{9fa5}]+$", strings.Trim(str, " ")); !m {
+			return errors.New("Please make sure that the chinese name only contains chinese characters.")
+		}
+	}
+	return nil
+}
+
+// Checks if a user name exist.
+func checkUsername(str string) error {
+	if strings.Trim(str, " ") == "" {
+		return errors.New("Please enter a username.")
+	}
+	return nil
+}
+
+// Check if age is a number and between 13 and 130
+func checkAge(str string) error {
+	age, err := strconv.Atoi(str)
+	if str == "" || err != nil {
+		return errors.New("Please enter a valid age.")
+	}
+	if age < 13 {
+		return errors.New("You must be at least 13 years of age to submit.")
+	}
+	if age > 130 {
+		return errors.New("You're too old to register, grandpa.")
+	}
+	return nil
+}
+func checkEmail(str string) error {
+	if m, err := regexp.MatchString(`^[^@]+@[^@]+$`, str); !m {
+		fmt.Println("err = ", err)
+		return errors.New("Please enter a valid email address.")
+	}
+	return nil
+}
+
+// Checks if a valid date was passed.
+func checkDate(str string) error {
+	_, err := time.Parse(mmddyyyyForm, str)
+	if err != nil {
+		_, err = time.Parse(yyyymmddForm, str)
+	}
+	if str == "" || err != nil {
+		return errors.New("Please enter a valid Date.")
+	}
+	return nil
+}
+
+// Checks if the passed input is a known gender option
+func checkGender(str string) error {
+	if str == "" {
+		return nil
+	}
+	siblings := []string{"m", "f", "na"}
+	if !isElementInSlice(str, siblings) {
+		return errors.New("Please select a valid gender.")
+	}
+	return nil
+}
+
+// Check if all the values are known options.
+func checkSibling(strs []string) error {
+	if strs == nil || len(strs) < 1 {
+		return nil
+	}
+	siblings := []string{"m", "f"}
+	if siblings != nil && !doSlicesIntersect(siblings, strs) {
+		return errors.New("Please select a valid sibling")
+	}
+	return nil
+}
+
+// Checks if the shirt size is a known option.
+func checkShirtSize(str string) error {
+	if str == "" {
+		return nil
+	}
+	shirts := []string{"s", "m", "l", "xl", "xxl"}
+	if !isElementInSlice(str, shirts) {
+		return errors.New("Please select a valid shirt size")
+	}
+	return nil
+}
--- a/fa/code/src/apps/ch.4.3/index.gtpl
+++ b/fa/code/src/apps/ch.4.3/index.gtpl
@@ -0,0 +1,28 @@
+<!doctype html>
+<html>
+	<body>
+		<h2>Cross Site Scripting Attack Test</h2>
+		{{if .}}
+		Previous User Input: <br/>
+		
+		<code><pre>{{.}}</pre></code>
+		{{end}}
+		<form action="/">
+			<label>
+				User Input: 
+				<input type="text" size=50 name="userinput" id="userinput"/>
+			</label>
+			<br/>
+			<label>
+				Escape Input: 
+				<input type="checkbox" value="1" name="escape" id="escape"/>
+			</label>
+			<br/>
+			<input type="submit" id="submitBtn" value="Submit"/>
+		</form>
+		<script type="text/javascript">
+		var s = "<scri"+"pt>alert('pOwned by XSS.')</scri"+"pt>"
+		document.getElementById("userinput").value = s;
+		</script>
+	</body>
+</html>
--- a/fa/code/src/apps/ch.4.3/main.go
+++ b/fa/code/src/apps/ch.4.3/main.go
@@ -0,0 +1,39 @@
+// Example code for Chapter 4.3 from "Build Web Application with Golang"
+// Purpose: Shows how to properly escape input
+package main
+
+import (
+	"html/template"
+	"net/http"
+	textTemplate "text/template"
+)
+
+var t *template.Template = template.Must(template.ParseFiles("index.gtpl"))
+
+func index(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()
+	userInput := r.Form.Get("userinput")
+	if 0 < len(r.Form.Get("escape")) {
+		t.Execute(w, template.HTMLEscapeString(userInput))
+	} else {
+		// Variables with type `template.HTML` are not escaped when passed to `.Execute()`
+		t.Execute(w, template.HTML(userInput))
+	}
+}
+func templateHandler(w http.ResponseWriter, r *http.Request) {
+	r.ParseForm()
+	userInput := r.Form.Get("userinput")
+	if 0 < len(r.Form.Get("escape")) {
+		// `html/template.Execute()` escapes input
+		t.Execute(w, userInput)
+	} else {
+		tt := textTemplate.Must(textTemplate.ParseFiles("index.gtpl"))
+		// `text/template.Execute()` doesn't escape input
+		tt.Execute(w, userInput)
+	}
+}
+func main() {
+	http.HandleFunc("/", index)
+	http.HandleFunc("/template", templateHandler)
+	http.ListenAndServe(":9090", nil)
+}
--- a/fa/code/src/apps/ch.4.4/main.go
+++ b/fa/code/src/apps/ch.4.4/main.go
@@ -0,0 +1,54 @@
+// Example code for Chapter 3.2 from "Build Web Application with Golang"
+// Purpose: Shows how to prevent duplicate submissions by using tokens
+// Example code for Chapter 4.4 based off the code from Chapter 4.2
+// Run `go run main.go` then access http://localhost:9090
+package main
+
+import (
+	"apps/ch.4.4/nonce"
+	"apps/ch.4.4/validator"
+	"html/template"
+	"log"
+	"net/http"
+)
+
+const (
+	PORT     = "9090"
+	HOST_URL = "http://localhost:" + PORT
+)
+
+var submissions nonce.Nonces
+var t *template.Template
+
+func index(w http.ResponseWriter, r *http.Request) {
+	http.Redirect(w, r, HOST_URL+"/profile", http.StatusTemporaryRedirect)
+}
+func profileHandler(w http.ResponseWriter, r *http.Request) {
+	t.ExecuteTemplate(w, "profile", submissions.NewNonce())
+}
+func checkProfile(w http.ResponseWriter, r *http.Request) {
+	var errs validator.Errors
+	r.ParseForm()
+	token := r.Form.Get("token")
+	if err := submissions.CheckThenMarkToken(token); err != nil {
+		errs = validator.Errors{[]error{err}}
+	} else {
+		p := validator.ProfilePage{&r.Form}
+		errs = p.GetErrors()
+	}
+	t.ExecuteTemplate(w, "submission", errs)
+}
+func init() {
+	submissions = nonce.New()
+	t = template.Must(template.ParseFiles("profile.gtpl", "submission.gtpl"))
+}
+func main() {
+	http.HandleFunc("/", index)
+	http.HandleFunc("/profile", profileHandler)
+	http.HandleFunc("/checkprofile", checkProfile)
+
+	err := http.ListenAndServe(":"+PORT, nil) // setting listening port
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}
--- a/fa/code/src/apps/ch.4.4/nonce/main.go
+++ b/fa/code/src/apps/ch.4.4/nonce/main.go
@@ -0,0 +1,70 @@
+// A nonce is a number or string used only once.
+// This is useful for generating a unique token for login pages to prevent duplicate submissions.
+package nonce
+
+import (
+	"crypto/md5"
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"strconv"
+	"time"
+)
+
+// Contains a unique token
+type Nonce struct {
+	Token string
+}
+
+// Keeps track of marked/used tokens
+type Nonces struct {
+	hashs map[string]bool
+}
+
+func New() Nonces {
+	return Nonces{make(map[string]bool)}
+}
+func (n *Nonces) NewNonce() Nonce {
+	return Nonce{n.NewToken()}
+}
+
+// Returns a new unique token
+func (n *Nonces) NewToken() string {
+	t := createToken()
+	for n.HasToken(t) {
+		t = createToken()
+	}
+	return t
+}
+
+// Checks if token has been marked.
+func (n *Nonces) HasToken(token string) bool {
+	return n.hashs[token] == true
+}
+func (n *Nonces) MarkToken(token string) {
+	n.hashs[token] = true
+}
+func (n *Nonces) CheckToken(token string) error {
+	if token == "" {
+		return errors.New("No token supplied")
+	}
+	if n.HasToken(token) {
+		return errors.New("Duplicate submission.")
+	}
+	return nil
+}
+func (n *Nonces) CheckThenMarkToken(token string) error {
+	defer n.MarkToken(token)
+	if err := n.CheckToken(token); err != nil {
+		return err
+	}
+	return nil
+}
+func createToken() string {
+	h := md5.New()
+	now := time.Now().Unix()
+	io.WriteString(h, strconv.FormatInt(now, 10))
+	io.WriteString(h, strconv.FormatInt(rand.Int63(), 10))
+	return fmt.Sprintf("%x", h.Sum(nil))
+}
--- a/fa/code/src/apps/ch.4.4/profile.gtpl
+++ b/fa/code/src/apps/ch.4.4/profile.gtpl
@@ -0,0 +1,85 @@
+{{define "profile"}}<!DOCTYPE html>
+<html>
+	<style>
+	.row{
+		display: table-row;
+	}
+	.cell{
+		display: table-cell;
+	}
+	.required{
+		color: red
+	}
+	</style>
+	<body>				
+		<h2>Profile Setup:</h2>
+		<form action="/checkprofile" method="POST">
+				<div class="row">
+					<div class="cell"><span class="required">*</span>User Name:</div>
+					<div class="cell"><input type="text" name="username" id="username" required/></div>
+				</div>
+				<div class="row">
+					<div class="cell"><span class="required">*</span>Age:</div>
+					<div class="cell"><input type="number" min="13" max="130" name="age" id="age" size="3" required/></div>
+				</div>
+				<div class="row">
+					<div class="cell"><span class="required">*</span>Email:</div>
+					<div class="cell"><input type="email" name="email" id="email" placeholder="john@example.com" required/></div>
+				</div>
+				<div class="row">
+					<div class="cell"><span class="required">*</span>Birth day:</div>
+					<div class="cell">
+						<input type="date" name="birthday" id="birthday" placeholder="MM/DD/YYYY" required/>
+					</div>
+				</div>
+				<div class="row">
+					<div class="cell">Gender:</div>
+					<div class="cell">
+						<label for="gender_male">
+							Male: <input type="radio" name="gender" value="m" id="gender_male"/>
+						</label>
+						<label for="gender_female">
+							Female: <input type="radio" name="gender" value="f" id="gender_female"/>
+						</label>
+						<label for="gender_na">
+							N/A: <input type="radio" name="gender" value="na" id="gender_na"/>
+						</label>
+					</div>
+				</div>
+				<div class="row">
+					<div class="cell">Siblings:</div>
+					<div class="cell">
+						<label for="sibling_male">
+							Brother: <input type="checkbox" name="sibling" value="m" id="sibling_male"/>
+						</label>
+						<label for="sibling_female">
+							Sister: <input type="checkbox" name="sibling" value="f" id="sibling_female"/>
+						</label>
+					</div>
+				</div>
+			<div class="row">
+				<div class="cell">Shirt Size:</div>
+				<div class="cell">
+					<select id="shirt_size" >
+						<option></option>
+						<option value="s">Small</option>
+						<option value="m">Medium</option>
+						<option value="l">Large</option>
+						<option value="xl">X-Large</option>
+						<option value="xxl">XX-Large</option>
+					</select>
+				</div>
+			</div>
+			<div class="row">
+				<div class="cell">Chinese Name:</div>
+				<div class="cell"><input type="text" name="chineseName" id="chineseName"/></div>
+			</div>
+			<br/>
+			<span class="required">*</span>Required
+			<br/>
+			<input type="hidden" name="token" value="{{.Token}}"/>
+			<input type="submit" value="Submit" id="submitBtn"/>
+		</form>
+	</body>
+</html>
+{{end}}
--- a/fa/code/src/apps/ch.4.4/submission.gtpl
+++ b/fa/code/src/apps/ch.4.4/submission.gtpl
@@ -0,0 +1,17 @@
+{{define "submission"}}<!DOCTYPE html>
+<html>
+	<body>
+		{{if .Errors}}
+		<h2>Errors:</h2>
+			<ol>
+				{{range .Errors}}	
+				<li>{{.}}</li>
+				{{end}}
+			</ol>	
+	{{else}}
+	Profile successfully submitted.<br/>
+	Note: Refreshing the page will produce a duplicate entry.
+	{{end}}
+	</body>
+</html>
+{{end}}
--- a/fa/code/src/apps/ch.4.4/validator/main.go
+++ b/fa/code/src/apps/ch.4.4/validator/main.go
@@ -0,0 +1,175 @@
+// This file contains all the validators to validate the profile page.
+package validator
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type ProfilePage struct {
+	Form *url.Values
+}
+type Errors struct {
+	Errors []error
+}
+
+// Goes through the form object and validates each element.
+// Attachs an error to the output if validation fails.
+func (p *ProfilePage) GetErrors() Errors {
+	errs := make([]error, 0, 10)
+	if *p.Form == nil || len(*p.Form) < 1 {
+		errs = append(errs, errors.New("No data was received. Please submit from the profile page."))
+	}
+	for name, val := range *p.Form {
+		if fn, ok := stringValidator[name]; ok {
+			if err := fn(strings.Join(val, "")); err != nil {
+				errs = append(errs, err)
+			}
+		} else {
+			if fn, ok := stringsValidator[name]; ok {
+				if err := fn(val); err != nil {
+					errs = append(errs, err)
+				}
+			}
+		}
+	}
+	return Errors{errs}
+}
+
+const (
+	// Used for parsing the time
+	mmddyyyyForm = "01/02/2006" // we want the date sent in this format
+	yyyymmddForm = "2006-01-02" // However, HTML5 pages send the date in this format
+)
+
+var stringValidator map[string]func(string) error = map[string]func(string) error{
+	// parameter name : validator reference
+	"age":         checkAge,
+	"birthday":    checkDate,
+	"chineseName": checkChineseName,
+	"email":       checkEmail,
+	"gender":      checkGender,
+	"shirtsize":   checkShirtSize,
+	"username":    checkUsername,
+}
+var stringsValidator map[string]func([]string) error = map[string]func([]string) error{
+	// parameter name : validator reference
+	"sibling": checkSibling,
+}
+
+// Returns true if slices have a common element
+func doSlicesIntersect(s1, s2 []string) bool {
+	if s1 == nil || s2 == nil {
+		return false
+	}
+	for _, str := range s1 {
+		if isElementInSlice(str, s2) {
+			return true
+		}
+	}
+	return false
+}
+func isElementInSlice(str string, sl []string) bool {
+	if sl == nil || str == "" {
+		return false
+	}
+	for _, v := range sl {
+		if v == str {
+			return true
+		}
+	}
+	return false
+}
+
+// Checks if all the characters are chinese characters. Won't check if empty.'
+func checkChineseName(str string) error {
+	if str != "" {
+		if m, _ := regexp.MatchString("^[\\x{4e00}-\\x{9fa5}]+$", strings.Trim(str, " ")); !m {
+			return errors.New("Please make sure that the chinese name only contains chinese characters.")
+		}
+	}
+	return nil
+}
+
+// Checks if a user name exist.
+func checkUsername(str string) error {
+	if strings.Trim(str, " ") == "" {
+		return errors.New("Please enter a username.")
+	}
+	return nil
+}
+
+// Check if age is a number and between 13 and 130
+func checkAge(str string) error {
+	age, err := strconv.Atoi(str)
+	if str == "" || err != nil {
+		return errors.New("Please enter a valid age.")
+	}
+	if age < 13 {
+		return errors.New("You must be at least 13 years of age to submit.")
+	}
+	if age > 130 {
+		return errors.New("You're too old to register, grandpa.")
+	}
+	return nil
+}
+func checkEmail(str string) error {
+	if m, err := regexp.MatchString(`^[^@]+@[^@]+$`, str); !m {
+		fmt.Println("err = ", err)
+		return errors.New("Please enter a valid email address.")
+	}
+	return nil
+}
+
+// Checks if a valid date was passed.
+func checkDate(str string) error {
+	_, err := time.Parse(mmddyyyyForm, str)
+	if err != nil {
+		_, err = time.Parse(yyyymmddForm, str)
+	}
+	if str == "" || err != nil {
+		return errors.New("Please enter a valid Date.")
+	}
+	return nil
+}
+
+// Checks if the passed input is a known gender option
+func checkGender(str string) error {
+	if str == "" {
+		return nil
+	}
+	siblings := []string{"m", "f", "na"}
+	if !isElementInSlice(str, siblings) {
+		return errors.New("Please select a valid gender.")
+	}
+	return nil
+}
+
+// Check if all the values are known options.
+func checkSibling(strs []string) error {
+	if strs == nil || len(strs) < 1 {
+		return nil
+	}
+	siblings := []string{"m", "f"}
+	if siblings != nil && !doSlicesIntersect(siblings, strs) {
+		return errors.New("Please select a valid sibling")
+	}
+	return nil
+}
+
+// Checks if the shirt size is a known option.
+func checkShirtSize(str string) error {
+	if str == "" {
+		return nil
+	}
+	shirts := []string{"s", "m", "l", "xl", "xxl"}
+	if !isElementInSlice(str, shirts) {
+		return errors.New("Please select a valid shirt size")
+	}
+	return nil
+}
--- a/fa/code/src/apps/ch.4.5/client_upload/main.go
+++ b/fa/code/src/apps/ch.4.5/client_upload/main.go
@@ -0,0 +1,46 @@
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"mime/multipart"
+	"net/http"
+	"os"
+)
+
+func checkError(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+func postFile(filename string, targetUrl string) {
+	bodyBuf := &bytes.Buffer{}
+	bodyWriter := multipart.NewWriter(bodyBuf)
+	fileWriter, err := bodyWriter.CreateFormFile("uploadfile", filename)
+	checkError(err)
+
+	fh, err := os.Open(filename)
+	checkError(err)
+
+	_, err = io.Copy(fileWriter, fh)
+	checkError(err)
+
+	contentType := bodyWriter.FormDataContentType()
+	bodyWriter.Close()
+	resp, err := http.Post(targetUrl, contentType, bodyBuf)
+	checkError(err)
+
+	defer resp.Body.Close()
+	resp_body, err := ioutil.ReadAll(resp.Body)
+	checkError(err)
+
+	fmt.Println(resp.Status)
+	fmt.Println(string(resp_body))
+}
+func main() {
+	target_url := "http://localhost:9090/upload"
+	filename := "../file.txt"
+	postFile(filename, target_url)
+}
--- a/fa/code/src/apps/ch.4.5/index.gtpl
+++ b/fa/code/src/apps/ch.4.5/index.gtpl
@@ -0,0 +1,15 @@
+{{define "index"}}
+<!doctype html>
+<html>
+<head>
+    <title>Upload file</title>
+</head>
+<body>
+<form enctype="multipart/form-data" action="http://127.0.0.1:9090/upload" method="post">
+    <input type="file" name="uploadfile" />
+    <input type="hidden" name="token" value="{{.}}"/>
+    <input type="submit" value="upload" />
+</form>
+</body>
+</html>
+{{end}}
--- a/fa/code/src/apps/ch.4.5/main.go
+++ b/fa/code/src/apps/ch.4.5/main.go
@@ -0,0 +1,64 @@
+// Example code for Chapter 4.5
+// Purpose is to create a server to handle uploading files.
+package main
+
+import (
+	"apps/ch.4.4/nonce"
+	"apps/ch.4.4/validator"
+	"fmt"
+	"html/template"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"os"
+)
+
+const MiB_UNIT = 1 << 20
+
+var t *template.Template
+var submissions nonce.Nonces = nonce.New()
+
+func checkError(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+func indexHandler(w http.ResponseWriter, r *http.Request) {
+	err := t.ExecuteTemplate(w, "index", submissions.NewToken())
+	checkError(err)
+}
+func uploadHandler(w http.ResponseWriter, r *http.Request) {
+	var errs validator.Errors
+	r.ParseMultipartForm(32 * MiB_UNIT)
+	token := r.Form.Get("token")
+	if err := submissions.CheckThenMarkToken(token); err != nil {
+		errs = validator.Errors{[]error{err}}
+	} else {
+		file, handler, err := r.FormFile("uploadfile")
+		checkError(err)
+		saveUpload(file, handler)
+	}
+	err := t.ExecuteTemplate(w, "upload", errs)
+	checkError(err)
+}
+func saveUpload(file multipart.File, handler *multipart.FileHeader) {
+	defer file.Close()
+	fmt.Printf("Uploaded file info: %#v", handler.Header)
+	localFilename := fmt.Sprintf("./uploads/%v.%v", handler.Filename, submissions.NewToken())
+	f, err := os.OpenFile(localFilename, os.O_WRONLY|os.O_CREATE, 0666)
+	checkError(err)
+	defer f.Close()
+	_, err = io.Copy(f, file)
+	checkError(err)
+}
+func init() {
+	var err error
+	t, err = template.ParseFiles("index.gtpl", "upload.gtpl")
+	checkError(err)
+}
+func main() {
+	http.HandleFunc("/", indexHandler)
+	http.HandleFunc("/upload", uploadHandler)
+	err := http.ListenAndServe(":9090", nil)
+	checkError(err)
+}
--- a/fa/code/src/apps/ch.4.5/nonce/main.go
+++ b/fa/code/src/apps/ch.4.5/nonce/main.go
@@ -0,0 +1,70 @@
+// A nonce is a number or string used only once.
+// This is useful for generating a unique token for login pages to prevent duplicate submissions.
+package nonce
+
+import (
+	"crypto/md5"
+	"errors"
+	"fmt"
+	"io"
+	"math/rand"
+	"strconv"
+	"time"
+)
+
+// Contains a unique token
+type Nonce struct {
+	Token string
+}
+
+// Keeps track of marked/used tokens
+type Nonces struct {
+	hashs map[string]bool
+}
+
+func New() Nonces {
+	return Nonces{make(map[string]bool)}
+}
+func (n *Nonces) NewNonce() Nonce {
+	return Nonce{n.NewToken()}
+}
+
+// Returns a new unique token
+func (n *Nonces) NewToken() string {
+	t := createToken()
+	for n.HasToken(t) {
+		t = createToken()
+	}
+	return t
+}
+
+// Checks if token has been marked.
+func (n *Nonces) HasToken(token string) bool {
+	return n.hashs[token] == true
+}
+func (n *Nonces) MarkToken(token string) {
+	n.hashs[token] = true
+}
+func (n *Nonces) CheckToken(token string) error {
+	if token == "" {
+		return errors.New("No token supplied")
+	}
+	if n.HasToken(token) {
+		return errors.New("Duplicate submission.")
+	}
+	return nil
+}
+func (n *Nonces) CheckThenMarkToken(token string) error {
+	defer n.MarkToken(token)
+	if err := n.CheckToken(token); err != nil {
+		return err
+	}
+	return nil
+}
+func createToken() string {
+	h := md5.New()
+	now := time.Now().Unix()
+	io.WriteString(h, strconv.FormatInt(now, 10))
+	io.WriteString(h, strconv.FormatInt(rand.Int63(), 10))
+	return fmt.Sprintf("%x", h.Sum(nil))
+}
--- a/fa/code/src/apps/ch.4.5/upload.gtpl
+++ b/fa/code/src/apps/ch.4.5/upload.gtpl
@@ -0,0 +1,17 @@
+{{define "upload"}}<!DOCTYPE html>
+<html>
+	<body>
+		{{if .Errors}}
+		<h2>Errors:</h2>
+			<ol>
+				{{range .Errors}}	
+				<li>{{.}}</li>
+				{{end}}
+			</ol>	
+	{{else}}
+	File uploaded successfully.<br/>
+	Note: Refreshing the page will produce a duplicate entry.
+	{{end}}
+	</body>
+</html>
+{{end}}
--- a/fa/code/src/apps/ch.4.5/validator/main.go
+++ b/fa/code/src/apps/ch.4.5/validator/main.go
@@ -0,0 +1,175 @@
+// This file contains all the validators to validate the profile page.
+package validator
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+)
+
+type ProfilePage struct {
+	Form *url.Values
+}
+type Errors struct {
+	Errors []error
+}
+
+// Goes through the form object and validates each element.
+// Attachs an error to the output if validation fails.
+func (p *ProfilePage) GetErrors() Errors {
+	errs := make([]error, 0, 10)
+	if *p.Form == nil || len(*p.Form) < 1 {
+		errs = append(errs, errors.New("No data was received. Please submit from the profile page."))
+	}
+	for name, val := range *p.Form {
+		if fn, ok := stringValidator[name]; ok {
+			if err := fn(strings.Join(val, "")); err != nil {
+				errs = append(errs, err)
+			}
+		} else {
+			if fn, ok := stringsValidator[name]; ok {
+				if err := fn(val); err != nil {
+					errs = append(errs, err)
+				}
+			}
+		}
+	}
+	return Errors{errs}
+}
+
+const (
+	// Used for parsing the time
+	mmddyyyyForm = "01/02/2006" // we want the date sent in this format
+	yyyymmddForm = "2006-01-02" // However, HTML5 pages send the date in this format
+)
+
+var stringValidator map[string]func(string) error = map[string]func(string) error{
+	// parameter name : validator reference
+	"age":         checkAge,
+	"birthday":    checkDate,
+	"chineseName": checkChineseName,
+	"email":       checkEmail,
+	"gender":      checkGender,
+	"shirtsize":   checkShirtSize,
+	"username":    checkUsername,
+}
+var stringsValidator map[string]func([]string) error = map[string]func([]string) error{
+	// parameter name : validator reference
+	"sibling": checkSibling,
+}
+
+// Returns true if slices have a common element
+func doSlicesIntersect(s1, s2 []string) bool {
+	if s1 == nil || s2 == nil {
+		return false
+	}
+	for _, str := range s1 {
+		if isElementInSlice(str, s2) {
+			return true
+		}
+	}
+	return false
+}
+func isElementInSlice(str string, sl []string) bool {
+	if sl == nil || str == "" {
+		return false
+	}
+	for _, v := range sl {
+		if v == str {
+			return true
+		}
+	}
+	return false
+}
+
+// Checks if all the characters are chinese characters. Won't check if empty.'
+func checkChineseName(str string) error {
+	if str != "" {
+		if m, _ := regexp.MatchString("^[\\x{4e00}-\\x{9fa5}]+$", strings.Trim(str, " ")); !m {
+			return errors.New("Please make sure that the chinese name only contains chinese characters.")
+		}
+	}
+	return nil
+}
+
+// Checks if a user name exist.
+func checkUsername(str string) error {
+	if strings.Trim(str, " ") == "" {
+		return errors.New("Please enter a username.")
+	}
+	return nil
+}
+
+// Check if age is a number and between 13 and 130
+func checkAge(str string) error {
+	age, err := strconv.Atoi(str)
+	if str == "" || err != nil {
+		return errors.New("Please enter a valid age.")
+	}
+	if age < 13 {
+		return errors.New("You must be at least 13 years of age to submit.")
+	}
+	if age > 130 {
+		return errors.New("You're too old to register, grandpa.")
+	}
+	return nil
+}
+func checkEmail(str string) error {
+	if m, err := regexp.MatchString(`^[^@]+@[^@]+$`, str); !m {
+		fmt.Println("err = ", err)
+		return errors.New("Please enter a valid email address.")
+	}
+	return nil
+}
+
+// Checks if a valid date was passed.
+func checkDate(str string) error {
+	_, err := time.Parse(mmddyyyyForm, str)
+	if err != nil {
+		_, err = time.Parse(yyyymmddForm, str)
+	}
+	if str == "" || err != nil {
+		return errors.New("Please enter a valid Date.")
+	}
+	return nil
+}
+
+// Checks if the passed input is a known gender option
+func checkGender(str string) error {
+	if str == "" {
+		return nil
+	}
+	siblings := []string{"m", "f", "na"}
+	if !isElementInSlice(str, siblings) {
+		return errors.New("Please select a valid gender.")
+	}
+	return nil
+}
+
+// Check if all the values are known options.
+func checkSibling(strs []string) error {
+	if strs == nil || len(strs) < 1 {
+		return nil
+	}
+	siblings := []string{"m", "f"}
+	if siblings != nil && !doSlicesIntersect(siblings, strs) {
+		return errors.New("Please select a valid sibling")
+	}
+	return nil
+}
+
+// Checks if the shirt size is a known option.
+func checkShirtSize(str string) error {
+	if str == "" {
+		return nil
+	}
+	shirts := []string{"s", "m", "l", "xl", "xxl"}
+	if !isElementInSlice(str, shirts) {
+		return errors.New("Please select a valid shirt size")
+	}
+	return nil
+}
--- a/fa/code/src/apps/ch.5.2/main.go
+++ b/fa/code/src/apps/ch.5.2/main.go
@@ -0,0 +1,76 @@
+// Example code for Chapter 5.2 from "Build Web Application with Golang"
+// Purpose: Use SQL driver to perform simple CRUD operations.
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	_ "github.com/go-sql-driver/mysql"
+)
+
+const (
+	DB_USER     = "user"
+	DB_PASSWORD = ""
+	DB_NAME     = "test"
+)
+
+func main() {
+	dbSouce := fmt.Sprintf("%v:%v@/%v?charset=utf8", DB_USER, DB_PASSWORD, DB_NAME)
+	db, err := sql.Open("mysql", dbSouce)
+	checkErr(err)
+	defer db.Close()
+
+	fmt.Println("Inserting")
+	stmt, err := db.Prepare("INSERT userinfo SET username=?,departname=?,created=?")
+	checkErr(err)
+
+	res, err := stmt.Exec("astaxie", "software developement", "2012-12-09")
+	checkErr(err)
+
+	id, err := res.LastInsertId()
+	checkErr(err)
+
+	fmt.Println("id of last inserted row =", id)
+	fmt.Println("Updating")
+	stmt, err = db.Prepare("update userinfo set username=? where uid=?")
+	checkErr(err)
+
+	res, err = stmt.Exec("astaxieupdate", id)
+	checkErr(err)
+
+	affect, err := res.RowsAffected()
+	checkErr(err)
+
+	fmt.Println(affect, "row(s) changed")
+
+	fmt.Println("Querying")
+	rows, err := db.Query("SELECT * FROM userinfo")
+	checkErr(err)
+
+	for rows.Next() {
+		var uid int
+		var username, department, created string
+		err = rows.Scan(&uid, &username, &department, &created)
+		checkErr(err)
+		fmt.Println("uid | username | department | created")
+		fmt.Printf("%3v | %6v | %6v | %6v\n", uid, username, department, created)
+	}
+
+	fmt.Println("Deleting")
+	stmt, err = db.Prepare("delete from userinfo where uid=?")
+	checkErr(err)
+
+	res, err = stmt.Exec(id)
+	checkErr(err)
+
+	affect, err = res.RowsAffected()
+	checkErr(err)
+
+	fmt.Println(affect, "row(s) changed")
+}
+
+func checkErr(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
--- a/fa/code/src/apps/ch.5.2/readme.md
+++ b/fa/code/src/apps/ch.5.2/readme.md
@@ -0,0 +1,12 @@
+## Setup for `ch.5.2`
+
+- Step 1) Install and run MySql
+- Step 2) Create a user and database according to the constants in `main.go`
+
+		DB_USER     = "user"
+		DB_PASSWORD = ""
+		DB_NAME     = "test"
+
+- Step 3) Create table `userinfo` located at `schema.sql`
+- Step 4) Run `go get` to download and install the remote packages.
+- Step 5) Execute the program with `go run main.go`
--- a/fa/code/src/apps/ch.5.2/schema.sql
+++ b/fa/code/src/apps/ch.5.2/schema.sql
@@ -0,0 +1,7 @@
+CREATE TABLE `userinfo` (
+	    `uid` INT(10) NOT NULL AUTO_INCREMENT,
+	    `username` VARCHAR(64) NULL DEFAULT NULL,
+	    `departname` VARCHAR(64) NULL DEFAULT NULL,
+	    `created` DATE NULL DEFAULT NULL,
+	    PRIMARY KEY (`uid`)
+);
--- a/fa/code/src/apps/ch.5.3/foo.db
+++ b/fa/code/src/apps/ch.5.3/foo.db
--- a/fa/code/src/apps/ch.5.3/main.go
+++ b/fa/code/src/apps/ch.5.3/main.go
@@ -0,0 +1,72 @@
+// Example code for Chapter 5.3 from "Build Web Application with Golang"
+// Purpose: Shows how to run simple CRUD operations using a sqlite driver
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	_ "github.com/mattn/go-sqlite3"
+	"time"
+)
+
+const DB_PATH = "./foo.db"
+
+func main() {
+	db, err := sql.Open("sqlite3", DB_PATH)
+	checkErr(err)
+	defer db.Close()
+
+	fmt.Println("Inserting")
+	stmt, err := db.Prepare("INSERT INTO userinfo(username, department, created) values(?,?,?)")
+	checkErr(err)
+
+	res, err := stmt.Exec("astaxie", "software developement", time.Now().Format("2006-01-02"))
+	checkErr(err)
+
+	id, err := res.LastInsertId()
+	checkErr(err)
+
+	fmt.Println("id of last inserted row =", id)
+	fmt.Println("Updating")
+	stmt, err = db.Prepare("update userinfo set username=? where uid=?")
+	checkErr(err)
+
+	res, err = stmt.Exec("astaxieupdate", id)
+	checkErr(err)
+
+	affect, err := res.RowsAffected()
+	checkErr(err)
+
+	fmt.Println(affect, "row(s) changed")
+
+	fmt.Println("Querying")
+	rows, err := db.Query("SELECT * FROM userinfo")
+	checkErr(err)
+
+	for rows.Next() {
+		var uid int
+		var username, department, created string
+		err = rows.Scan(&uid, &username, &department, &created)
+		checkErr(err)
+		fmt.Println("uid | username | department | created")
+		fmt.Printf("%3v | %6v | %8v | %6v\n", uid, username, department, created)
+	}
+
+	fmt.Println("Deleting")
+	stmt, err = db.Prepare("delete from userinfo where uid=?")
+	checkErr(err)
+
+	res, err = stmt.Exec(id)
+	checkErr(err)
+
+	affect, err = res.RowsAffected()
+	checkErr(err)
+
+	fmt.Println(affect, "row(s) changed")
+}
+
+func checkErr(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
--- a/fa/code/src/apps/ch.5.3/readme.md
+++ b/fa/code/src/apps/ch.5.3/readme.md
@@ -0,0 +1,23 @@
+## Set up for `ch.5.3`
+
+- Step 1) Download and install sqlite 3.
+- Step 2) Run `sqlite3 foo.db` to create a databased called `foo`.
+- Step 3) Create the `userinfo` table in sqlite using `schema.sql`.
+
+	Read and run sql statements 
+
+		sqlite> .read schema.sql
+
+	Show tables
+
+		sqlite> .tables
+		userinfo
+
+
+- Step 4) Exit sqlite.
+
+		sqlite> .exit
+
+- Step 5) Run `go get` to download and install remote packages.
+- Step 6) Run the program with `go run main.go`
+
--- a/fa/code/src/apps/ch.5.3/schema.sql
+++ b/fa/code/src/apps/ch.5.3/schema.sql
@@ -0,0 +1,6 @@
+CREATE TABLE `userinfo` (
+			`uid` INTEGER PRIMARY KEY AUTOINCREMENT,
+			`username` VARCHAR(64) NULL,
+			`department` VARCHAR(64) NULL,
+			`created` DATE NULL
+	);
--- a/fa/code/src/apps/ch.5.4/main.go
+++ b/fa/code/src/apps/ch.5.4/main.go
@@ -0,0 +1,78 @@
+// Example code for Chapter 5.4 from "Build Web Application with Golang"
+// Purpose: Show how to perform CRUD operations using a postgres driver
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"time"
+
+	_ "github.com/lib/pq"
+)
+
+const (
+	DB_USER     = "user"
+	DB_PASSWORD = ""
+	DB_NAME     = "test"
+)
+
+func main() {
+	dbinfo := fmt.Sprintf("user=%s password=%s dbname=%s sslmode=disable",
+		DB_USER, DB_PASSWORD, DB_NAME)
+	db, err := sql.Open("postgres", dbinfo)
+	checkErr(err)
+	defer db.Close()
+
+	fmt.Println("# Inserting values")
+
+	var lastInsertId int
+	err = db.QueryRow("INSERT INTO userinfo(username,departname,created) VALUES($1,$2,$3) returning uid;",
+		"astaxie", "software developement", "2012-12-09").Scan(&lastInsertId)
+	checkErr(err)
+	fmt.Println("id of last inserted row =", lastInsertId)
+
+	fmt.Println("# Updating")
+	stmt, err := db.Prepare("update userinfo set username=$1 where uid=$2")
+	checkErr(err)
+
+	res, err := stmt.Exec("astaxieupdate", lastInsertId)
+	checkErr(err)
+
+	affect, err := res.RowsAffected()
+	checkErr(err)
+
+	fmt.Println(affect, "row(s) changed")
+
+	fmt.Println("# Querying")
+	rows, err := db.Query("SELECT * FROM userinfo")
+	checkErr(err)
+
+	for rows.Next() {
+		var uid int
+		var username string
+		var department string
+		var created time.Time
+		err = rows.Scan(&uid, &username, &department, &created)
+		checkErr(err)
+		fmt.Println("uid | username | department | created ")
+		fmt.Printf("%3v | %8v | %6v | %6v\n", uid, username, department, created)
+	}
+
+	fmt.Println("# Deleting")
+	stmt, err = db.Prepare("delete from userinfo where uid=$1")
+	checkErr(err)
+
+	res, err = stmt.Exec(lastInsertId)
+	checkErr(err)
+
+	affect, err = res.RowsAffected()
+	checkErr(err)
+
+	fmt.Println(affect, "row(s) changed")
+}
+
+func checkErr(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
--- a/fa/code/src/apps/ch.5.4/readme.md
+++ b/fa/code/src/apps/ch.5.4/readme.md
@@ -0,0 +1,12 @@
+## Setup for ch.5.4
+
+- Step 1) Install and run Postgres
+- Step 2) Create a user and database according to the constants in `main.go`
+	
+		DB_USER     = "user"
+		DB_PASSWORD = ""
+		DB_NAME     = "test"
+
+- Step 3) Create table `userinfo` located at `schema.sql`
+- Step 4) Run `go get` to download and install the remote packages.
+- Step 5) Execute the program with `go run main.go`
--- a/fa/code/src/apps/ch.5.4/schema.sql
+++ b/fa/code/src/apps/ch.5.4/schema.sql
@@ -0,0 +1,9 @@
+CREATE TABLE userinfo
+(
+	    uid serial NOT NULL,
+	    username character varying(100) NOT NULL,
+	    departname character varying(500) NOT NULL,
+	    Created date,
+	    CONSTRAINT userinfo_pkey PRIMARY KEY (uid)
+)
+WITH (OIDS=FALSE);
--- a/fa/code/src/apps/ch.5.5/main.go
+++ b/fa/code/src/apps/ch.5.5/main.go
@@ -0,0 +1,170 @@
+// Example code for Chapter 5.5
+// Purpose is to show to use BeeDB ORM for basic CRUD operations for sqlite3
+package main
+
+import (
+	"database/sql"
+	"fmt"
+	"github.com/astaxie/beedb"
+	_ "github.com/mattn/go-sqlite3"
+	"time"
+)
+
+var orm beedb.Model
+
+type Userinfo struct {
+	Uid        int `beedb:"PK"`
+	Username   string
+	Department string
+	Created    string
+}
+
+const DB_PATH = "./foo.db"
+
+func checkError(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+func getTimeStamp() string {
+	return time.Now().Format("2006-01-02 15:04:05")
+}
+func insertUsingStruct() int64 {
+	fmt.Println("insertUsingStruct()")
+	var obj Userinfo
+	obj.Username = "Test Add User"
+	obj.Department = "Test Add Department"
+	obj.Created = getTimeStamp()
+	checkError(orm.Save(&obj))
+	fmt.Printf("%+v\n", obj)
+	return int64(obj.Uid)
+}
+func insertUsingMap() int64 {
+	fmt.Println("insertUsingMap()")
+	add := make(map[string]interface{})
+	add["username"] = "astaxie"
+	add["department"] = "cloud develop"
+	add["created"] = getTimeStamp()
+	id, err := orm.SetTable("userinfo").Insert(add)
+	checkError(err)
+	fmt.Println("Last row inserted id =", id)
+	return id
+}
+
+func getOneUserInfo(id int64) Userinfo {
+	fmt.Println("getOneUserInfo()")
+	var obj Userinfo
+	checkError(orm.Where("uid=?", id).Find(&obj))
+	return obj
+}
+
+func getAllUserInfo(id int64) []Userinfo {
+	fmt.Println("getAllUserInfo()")
+	var alluser []Userinfo
+	checkError(orm.Limit(10).Where("uid>?", id).FindAll(&alluser))
+	return alluser
+}
+
+func updateUserinfo(id int64) {
+	fmt.Println("updateUserinfo()")
+	var obj Userinfo
+	obj.Uid = int(id)
+	obj.Username = "Update Username"
+	obj.Department = "Update Department"
+	obj.Created = getTimeStamp()
+	checkError(orm.Save(&obj))
+	fmt.Printf("%+v\n", obj)
+}
+
+func updateUsingMap(id int64) {
+	fmt.Println("updateUsingMap()")
+	t := make(map[string]interface{})
+	t["username"] = "updateastaxie"
+	//update one
+	// id, err := orm.SetTable("userinfo").SetPK("uid").Where(2).Update(t)
+	//update batch
+	lastId, err := orm.SetTable("userinfo").Where("uid>?", id).Update(t)
+	checkError(err)
+	fmt.Println("Last row updated id =", lastId)
+}
+
+func getMapsFromSelect(id int64) []map[string][]byte {
+	fmt.Println("getMapsFromSelect()")
+	//Original SQL Backinfo resultsSlice []map[string][]byte
+	//default PrimaryKey id
+	c, err := orm.SetTable("userinfo").SetPK("uid").Where(id).Select("uid,username").FindMap()
+	checkError(err)
+	fmt.Printf("%+v\n", c)
+	return c
+}
+
+func groupby() {
+	fmt.Println("groupby()")
+	//Original SQL Group By
+	b, err := orm.SetTable("userinfo").GroupBy("username").Having("username='updateastaxie'").FindMap()
+	checkError(err)
+	fmt.Printf("%+v\n", b)
+}
+
+func joinTables(id int64) {
+	fmt.Println("joinTables()")
+	//Original SQL Join Table
+	a, err := orm.SetTable("userinfo").Join("LEFT", "userdetail", "userinfo.uid=userdetail.uid").Where("userinfo.uid=?", id).Select("userinfo.uid,userinfo.username,userdetail.profile").FindMap()
+	checkError(err)
+	fmt.Printf("%+v\n", a)
+}
+
+func deleteWithUserinfo(id int64) {
+	fmt.Println("deleteWithUserinfo()")
+	obj := getOneUserInfo(id)
+	id, err := orm.Delete(&obj)
+	checkError(err)
+	fmt.Println("Last row deleted id =", id)
+}
+
+func deleteRows() {
+	fmt.Println("deleteRows()")
+	//original SQL delete
+	id, err := orm.SetTable("userinfo").Where("uid>?", 2).DeleteRow()
+	checkError(err)
+	fmt.Println("Last row updated id =", id)
+}
+
+func deleteAllUserinfo(id int64) {
+	fmt.Println("deleteAllUserinfo()")
+	//delete all data
+	alluser := getAllUserInfo(id)
+	id, err := orm.DeleteAll(&alluser)
+	checkError(err)
+	fmt.Println("Last row updated id =", id)
+}
+func main() {
+	db, err := sql.Open("sqlite3", DB_PATH)
+	checkError(err)
+	orm = beedb.New(db)
+	var lastIdInserted int64
+
+	fmt.Println("Inserting")
+	lastIdInserted = insertUsingStruct()
+	insertUsingMap()
+
+	a := getOneUserInfo(lastIdInserted)
+	fmt.Println(a)
+
+	b := getAllUserInfo(lastIdInserted)
+	fmt.Println(b)
+
+	fmt.Println("Updating")
+	updateUserinfo(lastIdInserted)
+	updateUsingMap(lastIdInserted)
+
+	fmt.Println("Querying")
+	getMapsFromSelect(lastIdInserted)
+	groupby()
+	joinTables(lastIdInserted)
+
+	fmt.Println("Deleting")
+	deleteWithUserinfo(lastIdInserted)
+	deleteRows()
+	deleteAllUserinfo(lastIdInserted)
+}
--- a/fa/code/src/apps/ch.5.5/readme.md
+++ b/fa/code/src/apps/ch.5.5/readme.md
@@ -0,0 +1,23 @@
+## Set up for `ch.5.5`
+
+- Step 1) Download and install sqlite 3.
+- Step 2) Run `sqlite3 foo.db` to create a databased called `foo`.
+- Step 3) Create the tables found in `schema.sql` in sqlite.
+
+	Read and run sql statements 
+
+		sqlite> .read schema.sql
+
+	Show tables
+
+		sqlite> .tables
+		userinfo
+		userdetail
+
+- Step 4) Exit sqlite.
+
+		sqlite> .exit
+
+- Step 5) Run `go get` to download and install remote packages.
+- Step 6) Run the program with `go run main.go`
+
--- a/fa/code/src/apps/ch.5.5/schema.sql
+++ b/fa/code/src/apps/ch.5.5/schema.sql
@@ -0,0 +1,12 @@
+CREATE TABLE `userinfo` (
+	`uid` INTEGER PRIMARY KEY AUTOINCREMENT,
+	`username` VARCHAR(64) NULL,
+	`department` VARCHAR(64) NULL,
+	`created` DATE NULL
+);
+CREATE TABLE `userdetail` (
+	`uid` INT(10) NULL,
+	`intro` TEXT NULL,
+	`profile` TEXT NULL,
+	PRIMARY KEY (`uid`)
+);
--- a/fa/code/src/apps/ch.5.6/mongodb/main.go
+++ b/fa/code/src/apps/ch.5.6/mongodb/main.go
@@ -0,0 +1,58 @@
+// Example code for Chapter 5.6 from "Build Web Application with Golang"
+// Purpose: Shows you have to perform basic CRUD operations for a mongodb driver.
+package main
+
+import (
+	"fmt"
+	"labix.org/v2/mgo"
+	"labix.org/v2/mgo/bson"
+)
+
+type Person struct {
+	Name  string
+	Phone string
+}
+
+func checkError(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+const (
+	DB_NAME       = "test"
+	DB_COLLECTION = "people"
+)
+
+func main() {
+	session, err := mgo.Dial("localhost")
+	checkError(err)
+	defer session.Close()
+
+	session.SetMode(mgo.Monotonic, true)
+
+	c := session.DB(DB_NAME).C(DB_COLLECTION)
+	err = c.DropCollection()
+	checkError(err)
+
+	ale := Person{"Ale", "555-5555"}
+	cla := Person{"Cla", "555-1234"}
+
+	fmt.Println("Inserting")
+	err = c.Insert(&ale, &cla)
+	checkError(err)
+
+	fmt.Println("Updating")
+	ale.Phone = "555-0101"
+	err = c.Update(bson.M{"name": "Ale"}, &ale)
+
+	fmt.Println("Querying")
+	result := Person{}
+	err = c.Find(bson.M{"name": "Ale"}).One(&result)
+	checkError(err)
+	fmt.Println("Phone:", result.Phone)
+
+	fmt.Println("Deleting")
+	err = c.Remove(bson.M{"name": "Ale"})
+	checkError(err)
+}
--- a/fa/code/src/apps/ch.5.6/mongodb/readme.md
+++ b/fa/code/src/apps/ch.5.6/mongodb/readme.md
@@ -0,0 +1,6 @@
+## Setup for `ch.5.6` for MongoDB
+
+- Step 1) Install and run MongoDB
+- Step 2) Launch the MongoDB daemon (mongod) to start the server.
+- Step 3) Run `go get` to download and install the remote packages.
+- Step 4) Execute the program with `go run main.go`
--- a/fa/code/src/apps/ch.5.6/redis/main.go
+++ b/fa/code/src/apps/ch.5.6/redis/main.go
@@ -0,0 +1,60 @@
+// Example code for Chapter 5.6 from "Build Web Application with Golang"
+// Purpose: Shows you have to perform basic CRUD operations for a redis driver.
+package main
+
+import (
+	"fmt"
+	"github.com/astaxie/goredis"
+)
+
+func checkError(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+const (
+	DB_PORT = "9191"
+	DB_URL  = "127.0.0.1"
+)
+
+func main() {
+	var client goredis.Client
+
+	// Set the default port in Redis
+	client.Addr = DB_URL + ":" + DB_PORT
+
+	// string manipulation
+	fmt.Println("Inserting")
+	err := client.Set("a", []byte("hello"))
+	checkError(err)
+
+	// list operation
+	vals := []string{"a", "b", "c", "d"}
+	for _, v := range vals {
+		err = client.Rpush("l", []byte(v))
+		checkError(err)
+	}
+	fmt.Println("Updating")
+	err = client.Set("a", []byte("a is for apple"))
+	checkError(err)
+	err = client.Rpush("l", []byte("e"))
+	checkError(err)
+
+	fmt.Println("Querying")
+	val, err := client.Get("a")
+	checkError(err)
+	fmt.Println(string(val))
+
+	dbvals, err := client.Lrange("l", 0, 4)
+	checkError(err)
+	for i, v := range dbvals {
+		println(i, ":", string(v))
+	}
+
+	fmt.Println("Deleting")
+	_, err = client.Del("l")
+	checkError(err)
+	_, err = client.Del("a")
+	checkError(err)
+}
--- a/fa/code/src/apps/ch.5.6/redis/readme.md
+++ b/fa/code/src/apps/ch.5.6/redis/readme.md
@@ -0,0 +1,10 @@
+## Setup for `ch.5.6` for Redis
+
+- Step 1) Install and run Redis
+- Step 2) Launch the Redis server matching the DB constants.
+
+		DB_PORT = "9191"
+		DB_URL  = "127.0.0.1"
+
+- Step 3) Run `go get` to download and install the remote packages.
+- Step 4) Execute the program with `go run main.go`
--- a/fa/code/src/mymath/sqrt.go
+++ b/fa/code/src/mymath/sqrt.go
@@ -0,0 +1,12 @@
+// Example code for Chapter 1.2 from "Build Web Application with Golang"
+// Purpose: Shows how to create a simple package called `mymath`
+// This package must be imported from another go file to run.
+package mymath
+
+func Sqrt(x float64) float64 {
+	z := 0.0
+	for i := 0; i < 1000; i++ {
+		z -= (z*z - x) / (2 * x)
+	}
+	return z
+}