//switch

package main

import (

"fmt"

)

func main() {

switch os :="mysql"

os {

case "darwin":

fmt.Println("OS X.")

case "linux":

fmt.Println("Linux.")

case "mysql":

fmt.Println("mysql.")

default:

fmt.Printf("%s", os)

}

}

//for

package main

import ("fmt")

func main() {

for a:=1;a<=10;a++ {

fmt.Println(a)

}

}

//if判断

package main

import ("fmt")

func main() {

a := 9

if a<10 {

fmt.Println("比10小")

}else{

fmt.Println("大于等会10")

}

}