WaitGroup

In the previous exercise, we used a not-so-elegant method to ensure that the Goroutine ended by making the main Goroutine wait for a second. The important thing to understand is that even if a program does not explicitly use Goroutines via the go call, it still uses one Goroutine, which is the main routine. When we run our program and create a new Goroutine, we are running two Goroutines: the main one and the one we just created. In order to synchronize these two Goroutines, Go gives us a function called WaitGroup. You can define a WaitGroup using the following code:

wg := sync.WaitGroup{}

WaitGroup needs the sync package to be imported. Typical code using the WaitGroup will be something like this:

package main
import "sync"
func main() {
  wg := &sync.WaitGroup{}
  wg.Add(1)
  …………………..
  wg.Wait()
  ………….
  …...