go sync.WaitGroup

package main

import (
   "fmt"
   "sync"
)

func say(i int ,wg *sync.WaitGroup)  {
   defer wg.Done()
   fmt.Println(i)
}

func main() {
   var wg sync.WaitGroup
   for i:=0;i<1000;i++{
      wg.Add(1)
      go say(i,&wg)
   }
   fmt.Println(4444444)
   wg.Wait()

}