Closing channels

Context

You can close a channel with close(ch). Receivers can test whether a channel is closed using the comma‑ok idiom: v, ok := <-ch. Sending on a closed channel causes a panic.

Example

Close a channel and detect the closure.

Code example

package main

import "fmt"

func main() {
    ch := make(chan int, 2)
    ch <- 1
    ch <- 2
    close(ch)

    for i := 0; i < 3; i++ {
        v, ok := <-ch
        fmt.Printf("value=%d, ok=%t\n", v, ok)
    }
}

Output

value=1, ok=true
value=2, ok=true
value=0, ok=false

Useful links

• Go spec: Close
• Go by Example: Closing Channels