Go: What are channels in Go?

1// Unbuffered channel
2ch := make(chan int)
3
4// Send
5ch <- 42
6
7// Receive
8value := <-ch
9
10// Buffered channel
11ch := make(chan int, 10)
12ch <- 1  // Doesn't block until full
13ch <- 2

1// Send-only
2func send(ch chan<- int) {
3    ch <- 42
4}
5
6// Receive-only
7func receive(ch <-chan int) {
8    value := <-ch
9}

1close(ch)
2value, ok := <-ch  // ok = false when closed