fa directory created

fa/code/src/apps/ch.2.4/embedded_structs/main.go

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+// 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)
+}