// In the console
// First install jQuery
npm install --save jquery
// and jQuery Definition
npm install -D @types/jquery
// Now, within any of the app files (ES2015 style)
import * as $ from 'jquery';
//
$('#elemId').width();
// OR
// CommonJS style - working with "require"
import $ = require('jquery')
//
import $ from 'jquery';
//
$('#elemId').width();