title: Golang - Why use done channel
body: <p>It's one of example code of Golang. But cannot understand why 'done' channel need in this case.</p>
  
  <p><a href="https://gobyexample.com/closing-channels" rel="noreferrer">https://gobyexample.com/closing-channels</a></p>
  
  <p>There is no reason to sent true to done channel. We can know jobs channel is done when "sent all jobs" message is printed, isn't it?</p>
  
  <p>I deleted code that relative to done channel and result is still same.</p>
  
  <p><a href="https://play.golang.org/p/xOmzobFpTQ" rel="noreferrer">https://play.golang.org/p/xOmzobFpTQ</a></p>