Angular 5.0 change detection strategy VS React’s change detection strategy

Reference

-Angular

• Change detection is triggered by Zone.js at the end of each call stack in the zone. After callback to every async action, CD is triggered.
• CD starts from the root component and goes down through the components tree.
• ChangeDetectionStrategy.onPush to omit components and descendants during tree traversal.
• React
  • CD is triggered after callbacks of async actions.
  • CD starts from the component where setState was called.
  • Reconcile phase to traverse for checking which values need to be updated in real DOM.

Intercept @Input property change in Angular

Reference

• Typescript accessors via get and set.
• ngOnChanges.
• ngOnChanges is more “in-built”.

class MyComponent implements OnChanges {
  @Input() name: string;
  @Input() email: string;

  private username$ = new Subject<string>();

  ngOnChanges({ name, email }: SimpleChanges) { // ngOnChanges syntax
    const username = name.currentValue || email.currentValue;
    this.username$.next(username);
  }
}

• Reference - ngOnChanges gets you all the changes at once if your component has several @Input().
• Reference