How to make a string constant in angular 4?

Question

In my service, I am using a http post. I want to set the URL as a constant.

return this.http.get(this.config.API_URL+'users', options).map(res=>res.json());

I tried with a service:

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

@Injectable()
export class AppService {
  API_URL :String;

  constructor() {
    this.API_URL = 'some url';
  }
}

Is there any other method to make a constant value in Angular4 ?

Answer 1

I'm not sure if i understand your question but if you want to create constants, you can do it in a different class and import it.

constants.ts

export class Constants {
  public static get HOME_URL(): string { return "sample/url/"; };
}

sample.component.ts

   import { Constants } from "./constants";
    @Component({

    })
     export class SampleComponent {
      constructor() {
       let url = Constants.HOME_URL;
      }
    }