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JavaScript AJAX Basics Programming AJAX Create a callback

William Tunna
William Tunna
2,946 Points
Posted by William Tunna
William Tunna
2,946 Points

I don't understand why I'm getting a Parse error here

I'm not sure what I'm doing wrong here. The challenge is to create a onreadystatechange on line 2, with an anonymous function, but I'm getting a Parse Error

app.js 
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = () => {};
xhr.open('GET', 'sidebar.html');
xhr.send();
index.html 
<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <title>AJAX with JavaScript</title>
  <script src="app.js"></script>
</head>
<body>
  <div id="main">
    <h1>AJAX!</h1>
  </div>
  <div id="sidebar"></div>
</body>
</html>

1 Answer

Steven Parker
Steven Parker
231,275 Points
Steven Parker
Steven Parker
231,275 Points

This course was likely developed before ES2015 syntax was in common use. Try using a conventional function expression instead of an "arrow" function.

Even in modern code, arrow functions aren't always the best choice for handlers because they don't establish a value for "this" like conventional functions do.