lostecho/build-web-application-with-golang
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Make some rewordings

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vitkarpov
2015-02-26 21:00:18 +03:00
parent b0493cdba1
commit 47801e4ad9
2 changed files with 21 additions and 21 deletions
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38
en/02.3.md
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@@ -151,23 +151,23 @@ In the fifth line, we put many values in one `case`, and we don't need to add th
integer := 6
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")
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")
}
This program prints the following information.
@@ -295,13 +295,13 @@ Let's see one example in order to prove what i'm saying.
fmt.Println("x = ", x) // should print "x = 3"
}
Did you see that? Even though we called `add1`, and `add1` adds one to `a`, the value of `x` doesn't change.
Can you see that? Even though we called `add1` with `x`, the origin value of `x` doesn't change.
The reason is very simple: when we called `add1`, we gave a copy of `x` to it, not the `x` itself.
Now you may ask how I can pass the real `x` to the function.
We need use pointers here. We know variables are stored in memory and that they all have memory addresses. So, if we want to change the value of a variable, we must change the value at that variable's memory address. Therefore the function `add1` has to know the memory address of `x` in order to change its value. Here we pass `&x` to the function, and change the argument's type to the pointer type `*int`. Be aware that we pass a copy of the pointer, not copy of value.
We need use pointers here. We know variables are stored in memory and they have some memory addresses. So, if we want to change the value of a variable, we must change its memory address. Therefore the function `add1` has to know the memory address of `x` in order to change its value. Here we pass `&x` to the function, and change the argument's type to the pointer type `*int`. Be aware that we pass a copy of the pointer, not copy of value.
package main
import "fmt"