Broken Selector Checklist

Broken Selector Checklist: free step-by-step lesson with examples, common mistakes, and interview tips — part of jQuery Tutorial on Toolliyo Academy.

8 min read Updated 7/21/2026

On this page

jQuery Tutorial · Lesson 83 of 100

Broken Selector Checklist

Setup & DOM ✓ → Events Effects AJAX ✓ → Perf & Integrate ✓ → Ship & Projects

Ship & Projects · 4 — Build · ~10 min · Debug and Modernize

What is this?

Broken Selector Checklist improves debugging or plans a safer modernization path.

Why should you care?

Knowing when to keep or leave jQuery saves rewrites.

See it live — copy this example

Examples include the jQuery 3.7 CDN. Paste into an HTML file or use Run Example to preview.

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>QueryVerse</title>
  <style>
    body { font-family: system-ui, sans-serif; margin: 1.25rem; }
    .box { padding: .75rem; border: 1px solid #ccc; border-radius: 8px; margin: .5rem 0; }
    .muted { color: #666; }
    button { margin-right: .35rem; margin-top: .35rem; }
  </style>
</head>
<body>
  <p class="muted">Broken Selector Checklist</p>
  <button id="run">Inspect</button>
<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
<script>
$(function () {
  $('#run').on('click', function () {
    console.log('Debug checkpoint', $('#run').get(0));
    alert('Check the console for Broken Selector Checklist');
  });
});
</script>
</body>
</html>

Run Example »

Edit the code below and click Run to see the result in Toolliyo’s live editor.

Code

Result

What happened?

Reproduce in DevTools; migrate feature-by-feature; keep what still earns its keep.
Follow the steps below — typing the code yourself is the fastest way to learn.