sample.go

package main
import ("time")

func Producer(ch chan int) {
	for	i := 0; i < 5; i++ { ch <- i }
	println("close")
	close(ch)
}

func Consumer(ch1, _ chan int) {
	for {
		select {
			case x := <- ch1: {
				if x > 0 {
					println("ch1-", x)
				}
			}
			// case x := <- ch2: println("ch2-", x)
		}
	}
}

func main() {
	ch1, ch2 := make(chan int), make(chan int)
	go Producer(ch1)
	// go Producer(ch2)
	// Consumer(ch1, ch2)
	for {
		select {
			case x := <- ch1: {
				if x > 0 {
					println("ch1-", x)
				}
			}
			// case x := <- ch2: println("ch2-", x)
		}
	}
	time.Sleep(time.Second * 5)
}