non-blocking-channel-operations.go

package main

import "fmt"

func main() {
	messages := make(chan string)
	signals := make(chan bool)

	select {
		case msg := <-messages:
			fmt.Println("received messages", msg)
		default:
			fmt.Println("no message received")
	}

	msg := "hi"
	select {
		case messages <- msg:
			fmt.Println("sent message", msg)
		default:
			fmt.Println("no message sent")
	}

	select {
		case msg := <-messages:
			fmt.Println("received message", msg)
		case sig := <-signals:
			fmt.Println("received signal", sig)
		default:
			fmt.Println("no activity")
	}
}