Golang退出多层循环

Golang退出多层循环可以使用goto、break 标签实现，具体demo如下

package main

import (
	"time"
	"fmt"
	"sync"
)

func main() {
	var wg sync.WaitGroup
	wg.Add(2)
	go func() {
		gotoTest()
		wg.Done()
	}()

	go func() {
		breakTest()
		wg.Done()
	}()

	wg.Wait()
}

//goto 退出多层循环
func gotoTest() {
	ticker := time.NewTicker(time.Second * 2)
	timer := time.NewTimer(time.Second*9)
	for {
		select {
		case <-ticker.C:
			fmt.Println("====ticker  goto====")
		case <-timer.C:
			fmt.Println("goto exit")
			goto exit
		}
	}
exit:
	ticker.Stop()
	timer.Stop()
	fmt.Println("goto test over!")
}


//break 退出多层循环
func breakTest() {
	ticker := time.NewTicker(time.Second * 2)
	timer := time.NewTimer(time.Second*9)
	cycle:
	for {
		select {
		case <-ticker.C:
			fmt.Println("*********ticker  break********")
		case <-timer.C:
			fmt.Println("break exit")
			break cycle
		}
	}

	ticker.Stop()
	timer.Stop()
	fmt.Println("break test over!")
}