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) Traversing the DOM Child Traversal

Jase Hackman
Jase Hackman
4,320 Points
Posted by Jase Hackman
Jase Hackman
4,320 Points

I keep getting (evaluating 'newColor.style') error

I can't figure out why I am getting this error. As far as I can tell the code is running as it should. It is turning the paragraphs blue.

app.js 
const section = document.querySelector('section');
let paragraphs = section.children;

for (var i = 0; i <= paragraphs.length; i++) {
  var newColor = paragraphs[i];
  newColor.style.color = "blue";
}
index.html 
<!DOCTYPE html>
<html>
    <head>
        <title>Child Traversal</title>
    </head>
    <body>
        <section>
            <p>This is the first paragraph</p>
            <p>This is a slightly longer, second paragraph</p>
            <p>Shorter, last paragraph</p>
        </section>
        <footer>
            <p>&copy; 2016</p> 
        </footer>
        <script src="app.js"></script>
    </body>
</html>

1 Answer

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,967 Points

If you check the console you'll see Uncaught TypeError: Cannot read property 'style' of undefined. This comes from the upper bound of your for loop.

Instead of: 

i <= paragraphs.length

it should be

i < paragraphs.length
Jase Hackman
Jase Hackman
4,320 Points
Jase Hackman
Jase Hackman
4,320 Points

That fixed it! Thanks!