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) Responding to User Interaction Event Delegation

Michael Brown
Michael Brown
12,406 Points
Posted by Michael Brown
Michael Brown
12,406 Points

How to ensure only the list elements background color are changed?

I thought if I used an if-statement, it would only change the background of the text input. Am I not doing this right? I'm receiving an "undefined" error.

index.html 
<!DOCTYPE html>
<html>
    <head>
        <title>JavaScript and the DOM</title>
    </head>
    <link rel="stylesheet" href="style.css" />
    <body>
        <section>
            <h1>Making a Webpage Interactive</h1>
            <p>JavaScript is an exciting language that you can use to power web servers, create desktop programs, and even control robots. But JavaScript got its start in the browser way back in 1995.</p>
            <hr>
            <p>Things to Learn</p>
            <ul>
                <li>Item One: <input type="text"></li>
                <li>Item Two: <input type="text"></li>
                <li>Item Three: <input type="text"></li>
                <li>Item Four: <input type="text"></li>
            </ul>
            <button>Save</button>
        </section>
        <script src="app.js"></script>
    </body>
</html>
app.js 
let section = document.getElementsByTagName('section')[0];

section.addEventListener('click', (e) => {
  if(e.target.tagName = 'LI'){
  e.target.style.backgroundColor = 'rgb(255, 255, 0)';
  }
});

2 Answers

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

You have the right idea to test the tagName. But the instructions ask for "text input elements", not list items. So instead of checking for "LI", check for "INPUT" instead.

Also, remember that a single ("=") is an assignment. the comparison operator is ("==").

Tim Strand
Tim Strand
22,458 Points
Tim Strand
Tim Strand
22,458 Points

you are close. currently you only let li's through. you need to only let type = text through. try switching to e.target.type === 'text'

Also at minimum your if test should have 2 == not 1.

section.addEventListener('click', (e) => { if(e.target.tagName = 'LI'){ e.target.style.backgroundColor = 'rgb(255, 255, 0)'; } });

Michael Brown
Michael Brown
12,406 Points
Michael Brown
Michael Brown
12,406 Points

The "INPUT" and change of assignment to comparison operator fixed it. I appreciate the help. I've passed through to the next video.