ANGULAR calls the LIFECYCLE hook methods in the following sequence after creating a component/directive in Angular 6 by calling its constructor:

• ngOnChanges()
  This responds when Angular re-sets data-bound input properties.
• ngOnInit()
  Used to initialize the directive/component after Angular first displays the data-bound properties while setting the directive/component's input properties.
• ngDoCheck()
  Called during every change detection run, immediately after ngOnChanges() and ngOnInit() to detect and act upon changes that Angular won’t do on its own
• ngAfterContentInit()
  Called once after the first ngDoCheck() to respond after Angular projects external content into the component’s/directive’s view
• ngAfterContentChecked()
  Called after the ngAfterContentInit() and every SUBSEQUENT ngDoCheck() to respond after Angular checks the projected content.
• ngAfterViewInit()
  Called once after the first ngAfterContentChecked() to respond after Angular VALIDATES the component and it’s child views.
• ngAfterViewChecked()
  Called after the ngAfterViewInit() and after every subsequent ngAfterContentChecked().
• ngOnDestroy()
  Called just before Angular destroys the directive/component to avoid memory leaks by effective cleanup just before destroying the directives.