package main

import (

	"fmt"

	"time"

)

func main() {

	ch := make(chan int)

	quit := make(chan bool)

	//新开一个协程

	go func() {

		for {

			select {

			case num := <-ch:

				fmt.Println("num = ", num)

			case <-time.After(3 * time.Second):

				fmt.Println("超时")

				quit <- true

			}

		}

	}() //别忘了()

	for i := 0; i < 5; i++ {

		ch <- i

		time.Sleep(time.Second)

	}

	<-quit

	fmt.Println("程序结束")

}

num =  0

num =  1

num =  2

num =  3

num =  4

超时

程序结束