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JavaScript JavaScript and the DOM (Retiring) Getting a Handle on the DOM Practice Selecting Elements

Christopher Bate
Christopher Bate
4,736 Points
Posted by Christopher Bate
Christopher Bate
4,736 Points

Why doesn't this work? (chaining selectors)

Why doesn't this work?

let navigationLinks = document.getElementsByTagName('nav').getElementsByTagName('li');

js/app.js 
let navigationLinks = document.getElementsByTagName("nav").getElementsByTagName("li");
let galleryLinks;
let footerImages;
index.html 
<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>Nick Pettit | Designer</title>
    <link rel="stylesheet" href="css/normalize.css">
    <link href='http://fonts.googleapis.com/css?family=Changa+One|Open+Sans:400italic,700italic,400,700,800' rel='stylesheet' type='text/css'>
    <link rel="stylesheet" href="css/main.css">
    <link rel="stylesheet" href="css/responsive.css">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
  </head>
  <body>
    <header>
      <a href="index.html" id="logo">
        <h1>Nick Pettit</h1>
        <h2>Designer</h2>
      </a>
      <nav>
        <ul>
          <li><a href="index.html" class="selected">Portfolio</a></li>
          <li><a href="about.html">About</a></li>
          <li><a href="contact.html">Contact</a></li>
        </ul>
      </nav>
    </header>
    <div id="wrapper">
      <section>
        <ul id="gallery">
          <li>
            <a href="img/numbers-01.jpg">
              <img src="img/numbers-01.jpg" alt="">
              <p>Experimentation with color and texture.</p>
            </a>
          </li>
          <li>
            <a href="img/numbers-02.jpg">
              <img src="img/numbers-02.jpg" alt="">
              <p>Playing with blending modes in Photoshop.</p>
            </a>
          </li>
        </ul>
      </section>
      <footer>
        <a href="http://twitter.com/nickrp"><img src="img/twitter-wrap.png" alt="Twitter Logo" class="social-icon"></a>
        <a href="http://facebook.com/nickpettit"><img src="img/facebook-wrap.png" alt="Facebook Logo" class="social-icon"></a>
        <p>&copy; 2016 Nick Pettit.</p>
      </footer>
    </div>
  <script src="js/app.js"></script>
  </body>
</html>

2 Answers

Jason Anello
Jason Anello
Courses Plus Student 94,610 Points

Hi Christopher,

getElementsByTagName always returns an html collection even if only 1 element is found. This means you're calling the second getElementsByTagName on a collection but it needs to be called on an Element.

The nav element would be at index 0.

So you can do 

let navigationLinks = document.getElementsByTagName("nav")[0].getElementsByTagName("li");

The other problem is that it wanted the links within the nav, not the list items.

An easier way to do it would be to use querySelectorAll() and pass in the selector "nav a"

Christopher Bate
Christopher Bate
4,736 Points
Christopher Bate
Christopher Bate
4,736 Points

Thanks. I don't think the videos covered that you could use the querySelectorAll() with a query like that. I solved the rest using the similar pattern and man that is powerful!

Thanks