Can you explain the lifecycle hooks in Angular and when they are executed?
In Angular, a component goes through a series of steps, known as lifecycle hooks, from creation to destruction. Angular provides a number of lifecycle hooks that allow you to tap into these events and run custom logic. The lifecycle hooks are executed in a specific order and at specific times during the lifecycle of a component.
Here are some of the commonly used lifecycle hooks in Angular and when they are executed:
- ngOnChanges: This hook is executed when Angular detects changes to input properties of a component. It is executed after the constructor and before ngOnInit.
- ngOnInit: This hook is executed after the first ngOnChanges and is used for initializing the component after it has been created.
- ngDoCheck: This hook is executed during every Angular change detection cycle and is used for checking and updating the component based on custom logic.
- ngAfterContentInit: This hook is executed after Angular has processed the content projected into the component.
- ngAfterContentChecked: This hook is executed after Angular has checked the content projected into the component.
- ngAfterViewInit: This hook is executed after Angular has initialized the component’s views and child views.
- ngAfterViewChecked: This hook is executed after Angular has checked the component’s views and child views.
- ngOnDestroy: This hook is executed just before Angular destroys the component and is used for cleaning up any resources or subscriptions that the component has created.
By using these lifecycle hooks, you can add custom logic to your components and respond to events during their lifecycle, such as setting up subscriptions, updating data, or cleaning up resources.