switch语句的特点：
- 拥有多个分支
- switch后面可以不跟语句，在case的每个分支中直接添加
- 需要有
default语句
package main
import (
"fmt"
)
func eval(a, b int, op string) int{
var result int
switch op {
case " ":
result = a b
case "-":
result = a - b
case "*":
result = a * b
case "/":
result = a / b
default:
panic("unsupport operator:" op) // panic 自动报错机制
}
return result
}
func grade(score int ) string{
g := ""
switch { // switch 后面可以不跟表达式，直接在case中添加
case score < 0 || score > 100 :
panic(fmt.Sprintf("Wrong score: %d",score))
case score < 60:
g = "D"
case score < 80:
g = "C"
case score < 90:
g = "B"
case score < 100:
g = "A"
// default:
// panic(fmt.Sprintf("Wrong score: %d",score))
}
return g
}
func main(){
//猜手指
//finger := 3
//switch finger {
//case 1:
// fmt.Println("大拇指")
//case 2:
// fmt.Println("食指")
//case 3:
// fmt.Println("中指")
//case 4:
// fmt.Println("无名指")
//case 5:
// fmt.Println("小指")
//default:
// fmt.Println("无效输入")
////分支后面跟多个值
//number := 5
//switch number {
//case 1,3,5,7,9:
// fmt.Println("奇数")
//case 2,4,6,8,10:
// fmt.Println("偶数")
//default:
// fmt.Println("无效输入")
//}
result := eval(3, 5 ," ")
fmt.Println(result)
fmt.Println(grade(87))
//分支后面跟表达式
number := 5
switch {
case number % 2 == 0 :
fmt.Println("hello python")
case number % 2 == 1:
fmt.Println("hello Go")
default:
fmt.Println("无效输入")
}
}
