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

Posted by Carlos Marin
Carlos Marin
2,675 Points

IS there any other method I can use instead of QuerySelectorAll in this challenge?

I keep doing this challenge over and over again but it seems the only solution I was able to find was using the document.querySelectorAll method. I am trying to get to used to using the other methods of selecting in the DOM, but it seems like to select multiple elements with the other methods require a for loop. and when I try to use a for loop in this challenge it seems not to work. (I understand the challenge wants thenavigationLinks variable to store all the links.)

js/app.js 
let navigationLinks = document.querySelectorAll('nav a');
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>
Aurelian Spodarec
Aurelian Spodarec
10,801 Points
Aurelian Spodarec
Aurelian Spodarec
10,801 Points

Query selector and e.g. 'getElementsByClassName' store/get the data differently.

So you would need to do more work. Look inside the DOM how the data is stored.

3 Answers

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,971 Points

An alternate solution to querySelectorAll:

let navigationLinks = document.getElementsByTagName("nav")[0].getElementsByTagName("a");
Aurelian Spodarec
Aurelian Spodarec
10,801 Points
Aurelian Spodarec
Aurelian Spodarec
10,801 Points

How would you do it with class selector? Since it's a list of nodes, it won't work like querySelectorAll. So how would you extract that?

luther wardle
seal-mask
.a{fill-rule:evenodd;}techdegree
luther wardle
Full Stack JavaScript Techdegree Student 18,029 Points
luther wardle
.a{fill-rule:evenodd;}techdegree
luther wardle
Full Stack JavaScript Techdegree Student 18,029 Points

I'm curious why you would want to use another selector? Even though querySelectorAll can be loose, in this case its very direct since you have <a> tags inside your <li> tags

A solution to make the code "tighter" if you were doing this for a project would be to simply divide your <nav> tags into <navOne><navTwo> or make a <div> around them to access them by interacting with the div instead of the nav tag itself. although understandably, that makes the variable's name misleading.

Carlos Marin
Carlos Marin
2,675 Points

I read that using the QuerySelector methods can be 'loose' and it is preferred to use a more direct approach. I was unable to complete the DOM selection practice, so I came back to reinforce my understanding of the DOM.

Aurelian Spodarec
Aurelian Spodarec
10,801 Points
Aurelian Spodarec
Aurelian Spodarec
10,801 Points

It's simple...

Efficiency.

QuerySelectorAll looks for for 'ALL' items, while e.g. query selector class, looks for ONLY class items.

Guil talks about this, and it's best to use 'not' query selector all for efficiency purposes. It's easier to work with... but on a big project that can take it's hit.

Which means.. and the point of the question is... how do you do it with another selector?

It's the same story with re-inventing the wheel. Why would you do it? To learn.

ale8k
ale8k
8,299 Points
ale8k
ale8k
8,299 Points

You could grab them all under a new class/name

document.getElementsByClassName('[CLASS]');

// or name?

document.getElementsByName('[NAME]');

However depending on your program these can cause issues as they return a live HTML collection and querySelectors do not.

Aurelian Spodarec
Aurelian Spodarec
10,801 Points
Aurelian Spodarec
Aurelian Spodarec
10,801 Points

You don't put brackets inside the selector though.

ale8k
ale8k
8,299 Points
ale8k
ale8k
8,299 Points

The brackets are just representing what he could place there lol.