What is the lifecycle of an Angular application?

In Angular, the application lifecycle is the sequence of stages from the application loading in the browser to its destruction, during which Angular creates modules and components, binds data, and tracks changes.

#Key points

1. Bootstrap

• Angular initializes the root module (AppModule) and the root component (AppComponent).
• The component tree is created and services are injected through DI.

2. Creating components and modules

• For each component, the lifecycle hooks are called: ngOnChanges, ngOnInit, ngDoCheck, ngAfterContentInit, ngAfterViewInit, and so on.
• Angular builds the DOM structure based on templates and directives.

3. Change detection

• Angular tracks data changes and updates the DOM automatically.
• On a user event, an asynchronous operation, or a timer, Angular checks the components and updates the view.

4. User interaction

• Event handlers are called through (event) bindings, and data is updated through @Input and ngModel.
• Change detection ensures that changes are reflected in the templates.

5. Completion / destruction

• When the application or a component is removed, the ngOnDestroy() hook is called.
• Angular releases resources and unsubscribes from subscriptions.

In other words, the lifecycle of an Angular application is the full process of creating, rendering, updating, and completing the work of all the modules and components in the application.