13 if, switch, goto

if语句基本语法：

package main

import "fmt"

func main() {
	a := 5
	b := 6
	if a == b {
		fmt.Print("a is equal to b\n")
	} else {
		fmt.Print("a is not equal to b\n")
	}
}

switch语句基本语法:

package main

import "fmt"

func main() {
	stmt := "if"
	switch stmt {
	case "if", "for":
		fmt.Printf("stmt ('%s') is either 'if' or 'for'\n", stmt)
	case "else":
		fmt.Printf("stmt is 'else'\n")
	default:
		fmt.Printf("stmt is '%s'\n", stmt)
	}
}

注意，跟C++不同的是，case语句不会在条件落空后还到下个case，所以您不需要在每个case语句后面都放上break。

switch也被用作类型交换机(type switch)。