Angular 2 setters vs ngOnChanges

Issue

When you want to run some code after the component/directive inputs changes you can use setters or ngOnChanges hook, but what are the benefits of using one on the other? Or they are the same thing exactly?

  @Input()
  set someInput( val ) {
    this.runSomething();
  }

  ngOnChanges(changes) {
     this.runSomething();
  }

Solution

One advantage of ngOnChanges() is that you get all changes at once if your component has several @Input()s.
If your code only depends on a single @Input() a setter is probably the better approach.

Answered By - Günter Zöchbauer