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 AJAX Basics (retiring) Programming AJAX Check for the correct ready state

Posted by Susan Stufflebean
Susan Stufflebean
7,466 Points

Why is this not passing?

As you see I have added the correct code (I believe?) but when I check work it states my Task 1 is no longer passing? Why?

app.js 
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
if (xhr.readyState === 4 && xhr.status === 200){ xhr.status;
   document.getElementById('sidebar');.innerHTML = xhr.responseText;                                           
  };
};
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
231,172 Points
Steven Parker
Steven Parker
231,172 Points

Any syntax error invalidates the entire script and causes the re-validations to fail.

In this case, the error is the stray semicolon in this expression: "document.getElementById('sidebar');.innerHTML".

Also, while they don't cause errors, there are two more oddities in this code:

  • the statement "xhr.status;" doesn't do anything
  • there's a superfluous semicolon after the "if" code block