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JavaScript JavaScript and the DOM (Retiring) Getting a Handle on the DOM Select a Page Element By Its ID

Malika Sinkler
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Malika Sinkler
Full Stack JavaScript Techdegree Student 2,961 Points
Posted by Malika Sinkler
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Malika Sinkler
Full Stack JavaScript Techdegree Student 2,961 Points

I'm getting an Uncaught TypeError: Cannot read property 'addEventListener' of null. When clicking on the button.

const heading = document.getElementById('myHeading'); const button = document.getElementById('myButton');

button.addEventListener('click', () => {heading.style.color = 'red'; });

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,944 Points

Can you post your html?

2 Answers

Camilo Lucero
Camilo Lucero
27,692 Points
Camilo Lucero
Camilo Lucero
27,692 Points

Your JavaScript code is fine, this error means that the variable button is not linking correctly to your button.

In this case, I think that your problem might be in your HTML file. Check that your are linking the JS file in the HTML file, using the <script> tag with the attribute src pointing to your JS file:

<!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>
    <button id="myButton">Change color</button>
    <script src="app.js"></script>
  </body>
</html>