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JavaScript JavaScript and the DOM (Retiring) Traversing the DOM Child Traversal

Posted by Peter Logan
Peter Logan
2,597 Points

Doing the same action to children of a node through looping.

I don't understand what I am doing wrong! I am supposed to color all the p elements that are children of the section element by looping, but I messed something up. Can someone look at my code?

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

for (var i = 0; i <= paragraphs; i++) {
    paragraphs[i].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

Alexandra Barnett
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Alexandra Barnett
Front End Web Development Techdegree Graduate 46,473 Points
Alexandra Barnett
.a{fill-rule:evenodd;}techdegree seal-36
Alexandra Barnett
Front End Web Development Techdegree Graduate 46,473 Points

Hi Peter! You've almost got it! There are two small things that need to be changed:

  1. because your i variable starts at zero, the next part of the for loop will be i < paragraphs rather than <=. If you started i at 1, yours would be correct.
  2. As it's an array that you are looping through, it will be i < paragraphs.length because the code doesn't know how many times to loop round without a number (which is what .length gives you):
const section = document.querySelector('section');
let paragraphs = section.children;

for (var i = 0; i < paragraphs.length; i++) {
    paragraphs[i].style.color = "blue";
}

I hope that kind of makes sense :). Let me know if you have any questions!

Peter Logan
Peter Logan
2,597 Points

Thank you! I knew I was missing something simple.