@angular/core, @angular/common/http, @angular/router API Reference
Angular core APIs — the @Component decorator and lifecycle, HttpClient for HTTP, and the Router for navigation.
Component
The @Component decorator and related APIs for defining components, inputs/outputs, and lifecycle hooks.
@Component(metadata)Decorator that marks a class as an Angular component and attaches metadata (selector, template, styles).
Returns: ComponentDecorator
@Input() propertyMarks a class property as a data-bound input from a parent component's template.
Returns: InputDecorator
@Output() event = new EventEmitter<T>()Marks a property as an output that a parent component can bind to with event binding.
Returns: OutputDecorator
ngOnInit()Lifecycle hook called once after Angular initializes the data-bound properties of a directive.
Returns: void
ngOnDestroy()Lifecycle hook called once before Angular destroys the directive. Use for cleanup.
Returns: void
HttpClient
Angular's HttpClient for performing HTTP requests. Methods return cold observables.
http.get<T>(url, options?)Performs an HTTP GET request, emitting the response body.
Returns: Observable<T>
http.post<T>(url, body, options?)Performs an HTTP POST request with a request body.
Returns: Observable<T>
http.put<T>(url, body, options?)Performs an HTTP PUT request to replace a resource.
Returns: Observable<T>
http.delete<T>(url, options?)Performs an HTTP DELETE request.
Returns: Observable<T>
Router
Angular Router service for navigating between views and inspecting route state.
router.navigate(commands, extras?)Navigates based on an array of URL segments with optional navigation extras.
Returns: Promise<boolean>
router.navigateByUrl(url)Navigates using an absolute URL path string.
Returns: Promise<boolean>
route.snapshot.paramMap.get(key)Reads a route parameter synchronously from the activated route's snapshot.
Returns: string | null
router.eventsAn observable of router events (NavigationStart, NavigationEnd, etc.).
Returns: Observable<Event>