Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript JavaScript and the DOM Getting a Handle on the DOM Select by Tag Name

Bodie Wood
seal-mask
.a{fill-rule:evenodd;}techdegree
Bodie Wood
Full Stack JavaScript Techdegree Student 4,024 Points

Why doesnt `document.getElementsByTagName('ul');` work?

Hello!

I'm wondering why the code below doesn't work?

document.getElementsByTagName('ul');

Is this because 'ul' is singular?

I eventually answered this question correctly, but I need to know why the above statements doesn't work.

app.js
// Complete the challenge by writing JavaScript below
const colors = ["#C2272D", "#F8931F", "#FFFF01", "#009245", "#0193D9", "#0C04ED", "#612F90"];
let listItems = document.getElementsByTagName('li');

for ( let i = 0; i < colors.length; i++ ) {
  listItems[i].style.color = colors[i];    
}
index.html
<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">
    <title>JavaScript and the DOM</title>
  </head>
  <body>
    <h1>My List</h1>
    <ul>
      <li>This should be red</li>
      <li>This should be orange</li>
      <li>This should be yellow</li>
      <li>This should be green</li>
      <li>This should be blue</li>
      <li>This should be indigo</li>
      <li>This should be violet</li>
    </ul>
    <script src="app.js"></script>
  </body>
</html>

1 Answer

joseph weiss
joseph weiss
4,112 Points

That's because when you put "document.getElementsByTagName('ul');" you only select the parent element so you cant run thru it with the "for" loop because its just 1 "UL" and your not selecting the LI items. But when you select the "document.getElementsByTagName('li');" you select all LI elements, and then you can run thru it.