Services and Dependency Injection in Angular 16

In this article I will show you how to create a service in Angular 16 and use dependency injection to inject that service into any component that needs it.

What is a service?

Angular service is a clases which is designed for a focused purpose. A service provides a way for developers to separate Angular application data and functions/logic independently from any particular components that can be used by multiple components in the app.

How does a service work?

There are two different ways that a component can work with a service.

1 — Instantiate an instance

Component can create an instance of a service class and use it in that component. This approach is simple and it works; however, the instance of the service class is only local to the component on which it was instantiated. This approach makes it hard for sharing data, resources and will be difficult to mock up the service for testing. This technique is usually avoided by application architects.

2 — Register service

Register the service with Angular and Angular will then create a single instance of the service class. This is called the singleton pattern. This is achieved by…