[Golang] Wait For Goroutines to Finish

package main

import (
      "fmt"
)

func routine(site string, c chan int) {
      defer func() { c <- 1 }()

      // do something
      fmt.Println(site)
}

func main() {
      c := make(chan int)

      sites := []string{
              "https://www.google.com/",
              "https://duckduckgo.com/",
              "https://www.bing.com/"}

      for _, site := range sites {
              go routine(site, c)
      }

      // wait all goroutines to finish
      for i := 0; i < len(sites); i++ {
              <-c
      }
}

package main

import (
      "fmt"
      "sync"
)

var wg sync.WaitGroup

func routine(site string) {
      // Decrement the counter when the goroutine completes.
      defer wg.Done()

      // do something
      fmt.Println(site)
}

func main() {
      sites := []string{
              "https://www.google.com/",
              "https://duckduckgo.com/",
              "https://www.bing.com/"}

      for _, site := range sites {
              // Increment the WaitGroup counter.
              wg.Add(1)

              go routine(site)
      }

      // wait all goroutines to finish
      wg.Wait()
}