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Start your free trialAmy Tomey
12,847 Pointsapp.js:6 Uncaught TypeError: Cannot set property 'textContent' of null at HTMLButtonElement.<anonymous> (app.js:6)
I cannot find the error in the code that is causing the problem. It MUST be a tiny little thing...
<!DOCTYPE html>
<html>
<head>
<title>JavaScript and the DOM</title>
<link rel="stylesheet" href="css/style.css">
</head>
<body>
<h1 id="myHeading">JavaScript and the DOM</h1>
<p>Making a web page interactive</p>
<p class="description">Things that are purple:</p>
<input type="text" class="description">
<button class="description">Change list description</button>
<ul>
<li>grapes</li>
<li>amethyst</li>
<li>lavender</li>
<li>plums</li>
</ul>
<script src="app.js"></script>
</body>
</html>
And the JavaScript:
const input = document.querySelector ('input');
const p = document.querySelector ('description');
const button = document.querySelector ('button');
button.addEventListener ('click', ()=> {
p.textContent = input.value + ':';
})
Thanks in advance!
2 Answers
Jennifer Nordell
Treehouse TeacherHi there, Amy Tomey! You are correct. It is a tiny little thing. When picking by a class name in a querySelector()
it must be preceded by a .
or full stop/period.
You have this:
const p = document.querySelector ('description');
But you should have:
const p = document.querySelector('p.description'); // Note the p. before the description because you're picking the paragraph with a class of "description"
Hope this helps!
Blake Larson
13,014 PointsYou have all three of your elements you are grabbing with the same description
class name.
<!DOCTYPE html>
<html>
<head>
<title>JavaScript and the DOM</title>
<link rel="stylesheet" href="css/style.css">
</head>
<body>
<h1 id="myHeading">JavaScript and the DOM</h1>
<p>Making a web page interactive</p>
<p class="description">Things that are purple:</p>
<input type="text" class="input">
<button class="button">Change list description</button>
<ul>
<li>grapes</li>
<li>amethyst</li>
<li>lavender</li>
<li>plums</li>
</ul>
<script src="app.js"></script>
</body>
</html>
And just a period before the class name in the selector.
const input = document.querySelector ('.input');
const p = document.querySelector ('.description');
const button = document.querySelector ('.button');
button.addEventListener ('click', ()=> {
p.textContent = input.value + ':';
})