Angular·Angular from components to production

Services and dependency injection

Move shared logic into injectable services and inject them where needed.

Intermediate 13 min read Lesson 5 of 300 Challenge included

What you will be able to do

Create services with @Injectable.
Use providedIn: "root" for shared singletons.
Inject with the inject() function.
Keep HTTP and state logic out of components.

In plain English

A service is a class with a single responsibility. Angular’s injector creates it and hands it to consumers. Use providedIn: root for app-wide singletons and inject() for concise constructor-free injection.

courses.service.tsTYPESCRIPT

import { Injectable, inject } from '@angular/core'
import { HttpClient } from '@angular/common/http'

@Injectable({ providedIn: 'root' })
export class CoursesService {
  private http = inject(HttpClient)

  list() {
    return this.http.get<Course[]>('/api/courses')
  }
}

Your turn

Inject HttpClient

Easy

Add HttpClient to a service using inject().

TYPESCRIPT · starter

private http =

Check your understanding before moving on.

Knowledge checkQuestion 1

What does providedIn: "root" mean?

Select an answer to continue

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