title: Can not understand ngDoCheck method in lifecycle Hooks for component
body: <p>From Angular documentation:</p>
  <blockquote>
  <p>Detect and act upon changes that Angular can't or won't detect on its own.</p>
  <p>Called during every change detection run, immediately after ngOnChanges and ngOnInit.</p>
  </blockquote>
  <p>How this method can be <strong>called during every change detection run if angular can't or won't detect on its own</strong>?</p>
  <p>Can somebody explain and give an example?</p>