go - 为什么在go routine中关闭channel会导致receiving channel收到值？

Question

我有一个 go 例程，它会定期轮询每个时间间隔并执行操作。它还检查完成 channel ，作为结束信号，以停止轮询。

  go func(){
       for {
          select{
              case <-myticker.C:
                 do_something()
              case <-done:
                 fmt.Println("I am done")
                 return
         } 
       }

    }

我意识到如果我关闭 channel ，它也会运行，就好像值被传递给 done channel 一样，它打印出“我完成了”为什么会这样？

Answer 1

来自规范:

A receive operation on a closed channel can always proceed immediately, yielding the element type's zero value after any previously sent values have been received.

参见 https://golang.org/ref/spec#Receive_operator .