package main

import (
	"fmt"
	"time"
)

func printX() {
	for i := 0; i < 100; i++ {
		fmt.Print("X")
	}
}

func printY() {
	for i := 0; i < 100; i++ {
		fmt.Print("Y")
	}
}

func main() {
	fmt.Println("a goroutine is a **lightweight** thread managed by the go runtime")

	printX()
	fmt.Println()
	printY()
	fmt.Println()
	fmt.Println("you should see first X's then Y's")

	time.Sleep(100 * time.Millisecond)
	fmt.Println()
	fmt.Println()

	go printX()
	go printY()
	fmt.Println("you should see random X's and Y's, this because concurrency")

	time.Sleep(1 * time.Second)
	// wait for prevent main goroutine to terminate
}