Go by Example: Channel Buffering

By default channels are unbuffered, meaning that they will only accept sends (chan <-) if there is a corresponding receive (<- chan) ready to receive the sent value. Buffered channels accept a limited number of values without a corresponding receiver for those values.

package main
import "fmt"
func main() {

Here we make a channel of strings buffering up to 2 values.

    messages := make(chan string, 2)

Because this channel is buffered, we can send these values into the channel without a corresponding concurrent receive.

    messages <- "buffered"
    messages <- "channel"

Later we can receive these two values as usual.

$ go run channel-buffering.go 

Next example: Channel Synchronization.