package main

import (
	"fmt"
)

func main() {
	ch := make(chan int) //创建一个无缓存channel

	//新建一个goroutine
	go func() {
		for i := 0; i < 5; i++ {
			ch <- i //往通道写数据
		}
		//不需要再写数据时，关闭channel
		close(ch)
		//ch <- 666 //关闭channel后无法再发送数据

	}() //别忘了()

	for {
		//如果ok为true，说明管道没有关闭
		if num, ok := <-ch; ok == true {
			fmt.Println("num = ", num)
		} else { //管道关闭
			break
		}
	}
}

num =  0
num =  1
num =  2
num =  3
num =  4