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Begana Choi
Courses Plus Student 13,124 Pointswhy my code makes error? (add a class name)
here is my code and it says I have error that
There was an error with your code: TypeError: 'undefined' is not an object (evaluating 'p.className = 'highlight'')
and I have no idea why it's wrong.. please help meee thank you!!
var list = document.getElementsByTagName('ul')[0];
list.addEventListener('click', function(e) {
if (e.target.tagName == 'BUTTON') {
let button = event.target;
let p = button.previousElementSiblings;
p.className = 'highlight';
}
});
<!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>Things to Learn</p>
<ul>
<li><p>Element Selection</p><button>Highlight</button></li>
<li><p>Events</p><button>Highlight</button></li>
<li><p>Event Listening</p><button>Highlight</button></li>
<li><p>DOM Traversal</p><button>Highlight</button></li>
</ul>
</section>
<script src="app.js"></script>
</body>
</html>
1 Answer

KRIS NIKOLAISEN
54,663 PointsIt is just previousElementSibling
without the s at the end