Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

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

jiwan gurung
jiwan gurung
4,248 Points
Posted by jiwan gurung
jiwan gurung
4,248 Points

i am stuck.can anyone tell me the difference between getelementsbyid and queryselectorAll?

why do i need to target the <ul>,<li> tag inside the nav element? isnt just document.queryselectorAll('nav') goin to be enough to target all those elements? and also i am confused when and where we use getelementsbyid and queryselector. can anyone tell me the difference? thank you

js/app.js 
let navigationLinks = document.querySelectorAll("nav");
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>

1 Answer

Dale Severude
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Dale Severude
Full Stack JavaScript Techdegree Graduate 71,350 Points
Dale Severude
.a{fill-rule:evenodd;}techdegree seal-36
Dale Severude
Full Stack JavaScript Techdegree Graduate 71,350 Points

Hi Jiwan,

Document.getElementById will specifically select an element by it's id. It is important to remember that only one element is ever selected. For example, this HTML element with ID of btn

<button id="btn">Click Me</button>

can be selected by the following JavaScript statement which selects the ID of btn.

let clickMe = document.getElementById('btn');

Document.querySelectorAll will select a list of multiple elements. It returns a list of elements based on the query you give it. The answer you are giving will only select the nav element based on your query.

let navigationLinks = document.querySelectorAll("nav");

The challenge is asking only for the links located underneath the nav element. This is done the same way as selecting elements with CSS styling. To do this, add the a tag after the nav tag. With the below example ONLY the a tags are selected that are nested underneath nav. The nav element itself is NOT selected.

let navigationLinks = document.querySelectorAll("nav a");

I hope this makes sense.