title: Angular 2 setters vs ngOnChanges
body: <p>When you want to run some code after the component/directive inputs changes you can use setters or <code>ngOnChanges</code> hook, but what are the benefits of using one on the other? Or they are the same thing exactly? </p>
  
  <pre><code>  @Input()
    set someInput( val ) {
      this.runSomething();
    }
  
    ngOnChanges(changes) {
       this.runSomething();
    }
  </code></pre>