Some of the tricks that channel USES in Golang

Shut down 2 times

ch := make(chan bool) 

close(ch) 

close(ch)  //  It would be panic The, channel Can't close two  

When reading, channel was turned off prematurely

ch := make(chan string) 

close(ch) 

i := <- ch //  Don't panic, i The value read is empty  "",   if channel is bool Theta, so what we read is theta false 

Write data to channel that has been closed

ch := make(chan string) 

close(ch) 

ch <- "good" //  will panic the  

Determine if channel is close

i, ok := <- ch 

if ok { 

    println(i) 

} else { 

    println("channel closed") 

} 

for reads channel in a loop

for i := range ch { // ch Closing, for The loop ends automatically  

    println(i) 

} 

Prevent read timeout

select { 

    case <- time.After(time.Second*2): 

        println("read channel timeout") 

    case i := <- ch: 

        println(i) 

} 

Prevent write timeout

//  It's a lot like a read timeout  

select { 

    case <- time.After(time.Second *2): 

        println("write channel timeout") 

    case ch <- "hello": 

        println("write ok") 

}