WaitGroup

package main

import (

"fmt"

"strconv"

"sync"

)

var wg = sync.WaitGroup{}

func main() {

for i:=0; i<5; i++ {

wg.Add(1)

go sayHello(i)

}

wg.Wait()

fmt.Println("Done")

}

func sayHello(i int) {

fmt.Println("Hello" + strconv.Itoa(i));

wg.Done()

}

//

Hello4

Hello0

Hello1

Hello2

Hello3

Done