title: Angular 5 + Popper.JS
body: <p>I'm trying to launch training project that requires Popper.Js in its features. However, it doesn't seem to let me just start to use Popper.Js.</p>
  
  <p>According to Bootstrap's docs I start Popper.Js by </p>
  
  <pre><code>$(function () {
    $('[data-toggle="tooltip"]').tooltip();
  });
  </code></pre>
  
  <p>I use it in main component in <code>ngOnInit</code>. However, it doesn't work. The error occurs "<em>Property 'tooltip' does not exist on type 'JQuery'</em>". I imported jquery and bootstrap bundle file. Types for all the libraries are installed.</p>
  
  <p>I also tried the pure "popper.js" instead of bootstrap.bundle.js. But the same error occurs. Bootstrap.bundle.js(includes bootstrap and popper.js in right order) and jquery are imported in angular-cli.json.</p>