Question

angular difference between ngonchanges and ngdocheck

Answer 1

ngOnChanges() (OnChanges) is called when a value bound to an input has changed so you can run custom code when an input has changed.

ngDoCheck() (DoCheck) is called when change detection runs so you can implement your custom change detection action.

Answer 2

ngOnChanges is when the input value changes, whereas ngDoCheck() (DoCheck) is when a change detection is run.

• NgOnChanges) ((OnChanges) is called when an input-bound value has changed to allow the execution of custom code when the input changes.
• When a change detection runs, ngDoCheck) ((DoCheck) is called upon, so that one can enforce their custom change detection action.
• NgDocheck is used each time the detection period changes while ngOnChange only fires when there is a change in the component's bound model property