Angular & Signals (283 Qs)•Part 1: Architecture, Components, Directives & Lifecycle (1 - 35)
What is dependency injection in Angular?
Dependency injection (DI), is an important application design pattern in which a class asks for dependencies from external sources rather than creating them itself. Angular comes with its own dependency injection framework for resolving dependencies( services or objects that a class needs to perform its function).So you can have your services depend on other services throughout your application.
Practical Code Example
typescript
// Dependency Injection: Injecting services via constructor or modern inject() function
import { Component, inject } from '@angular/core';
import { UserService } from './user.service';
@Component({
selector: 'app-profile',
standalone: true,
template: `<div>User: {{ user().name }}</div>`
})
export class ProfileComponent {
// Modern Angular 14+ inject() pattern:
private userService = inject(UserService);
user = this.userService.currentUser;
}