In Angular, components have a lifecycle that consists of various phases and events. These phases are known as lifecycle hooks, and they provide opportunities to perform actions at specific moments during the component's creation, rendering, and destruction. The following are the lifecycle hooks available in an Angular component:
1. ngOnChanges: This hook is called when the component receives input properties and is executed before `ngOnInit()`. It allows you to react to changes in the input properties.
2. ngOnInit: This hook is called once, after the first `ngOnChanges()`, when the component is initialized. It is commonly used for initialization logic, such as retrieving data from a server.
3. ngDoCheck: This hook is called during every change detection run, allowing you to implement your own custom change detection logic. It is invoked frequently, so use it judiciously to avoid performance issues.
4. ngAfterContentInit: This hook is called after the component's content has been projected into its view. It is useful when you need to interact with content children components.
5. ngAfterContentChecked: This hook is called after the content of the component has been checked by Angular's change detection mechanism. It is called after every check of the content children.
6. ngAfterViewInit: This hook is called after the component's view has been initialized. It is useful when you need to interact with child components that are part of the view.
7. ngAfterViewChecked: This hook is called after the view of the component has been checked by Angular's change detection mechanism. It is called after every check of the component's view and its child views.
8. ngOnDestroy: This hook is called just before the component is destroyed and removed from the DOM. It is used to clean up resources, such as unsubscribing from observables or canceling timers.
These lifecycle hooks allow you to perform specific actions at different stages of a component's lifecycle. By implementing and using these hooks, you can control the behavior and manage resources effectively throughout the component's lifespan.