How Unbuffered channel work

[Manjeet S]

I just started to learn Go Language, and I'm enjoying writing code in Go.
So today, I'm trying to understand how the unbuffered channel works

Can someone help me to understand why this code is not working. I'm expecting that <-ch wait until we receive from channel ch

func main() {

    ch := make(chan struct{})

    ch2 := make(chan int)

   

    go func() {

        arr := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}

        for _, v := range arr {

            ch2 <- v

        }

    }()

    go func() {

        for t := range ch2 {

            fmt.Println(t)

        }

        ch <- struct{}{}

    }()

    <-ch

}

Thanks & Regards  

Manjeet Thakur

[pere...@gmail.com]

You did not close ch2 in the first goroutine. Therefore, the second goroutine never reaches line "ch <- struct{}{}"

Aleksei Perevozov

воскресенье, 5 июня 2022 г. в 16:06:53 UTC+2, manjee...@gmail.com:

[Jan Mercl]

On Sun, Jun 5, 2022 at 4:06 PM Manjeet S <manjee...@gmail.com> wrote:

> Can someone help me to understand why this code is not working. I'm expecting that <-ch wait until we receive from channel ch

The range statement at line 18 does not complete unless the channel is
closed. Adding `close(ch2)` at line 14 fixes the problem:
https://go.dev/play/p/OnmJD04VYDA

[Manjeet S]

Thank you so much  Aleksei Perevozov and Jan Mercl