Say you are fetching JSON data from an api url which is http://localhost:8080/api, and you have to use it for a a number of times
You can declare the variable as
export var API_ENDPOINT = 'http://localhost:8080/api';
and later you can call this variable as
return this._http.get(API_ENDPOINT+'/getLoggedUser')
Complete code example
import {Injectable} from 'angular2/core'; import {Http,Response,Headers} from 'angular2/http'; import 'rxjs/add/operator/map'; import {Observable} from 'rxjs/Observable'; import 'rxjs/Rx'; export var API_ENDPOINT = 'http://localhost:8080/api'; @Injectable() export class AppService{ constructor(private _http:Http){} getUsers(){ console.log("user info fetching"); return this._http.get(API_ENDPOINT+'/getLoggedUser') .map((res:Response)=>res.json()); } }