How to create a service in angular?

Services are same as class with a specific purpose of it. Services can contain method, property and any feature of an application which we can reuse multiple time in our web application. Services also contain a decorator which tell angular how to consume it in our application.

Let’s create a service.

Install a fresh or existing angular project and follow the steps:

Step 1 : Create a service

ng generate service logger

Above code will create a service in src\app\logger.service.ts or we can create manually

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class LoggerService {

  constructor() { }
}

Step 2 : Inject service in component

You can inject the service in new component or existing component and can use all the methods and properties of it.

import { Component } from '@angular/core';
import { LoggerService } from './logger.service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {

  title = 'Service Example';
  constructor(logger:LoggerService){

    logger.log("This is test")

  }  
}

Here, we import the LoggerService and injected it in constructor, then we can use the methods of LoggerService in this component.

Step 3 : Run and check in console

Run using angular command and check the simple use of services

ng serve

Advantages of service or dependency injection

1. Services are globally accessible by angular app
2. Using Dependency injection, Angular create the object once and share it with all component so it saves the memory and sustain the state.
3. Using Services we can communicate between n level component using EventEmitter.