Golang Concurrent - Go channels

ex_channel.go

package main

import (
	"fmt"
	"time"
)

func say(str string) {
	time.Sleep(1 * time.Millisecond)
	for i := 0; i < 10; i++ {
		fmt.Printf("%d) %v\n", i, str)
	}
}

func main() {
	go say("Hello")
	go say("World")
	go say("Bye")
	time.Sleep(100 * time.Millisecond)
}