Basic Selectors
Basic Selectors: free step-by-step lesson with examples, common mistakes, and interview tips — part of jQuery Tutorial on Toolliyo Academy.
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jQuery Tutorial · Lesson 5 of 100
Basic Selectors
Setup & DOM → Events Effects AJAX → Perf & Integrate → Ship & Projects
Setup & DOM · 1 — Select · ~6 min · Setup and Selectors
What is this?
Select nodes with CSS-like selectors: $("#id"), $(".class"), $("tag"), and combinations.
Why should you care?
Almost every QueryVerse action starts with finding the right elements.
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>
<ul id="list">
<li class="item">Alpha</li>
<li class="item active">Beta</li>
<li class="item">Gamma</li>
</ul>
<p id="out" class="muted"></p>
<script src="https://code.jquery.com/jquery-3.7.1.min.js"></script>
<script>
$(function () {
const n = $('#list .item').length;
const active = $('li.active').text();
$('#out').text(n + ' items; active=' + active);
});
</script>
</body>
</html>Run Example »
Edit the code below and click Run to see the result in Toolliyo’s live editor.
What happened?
- $ returns a jQuery collection.
- Chain methods on it.
- Prefer specific selectors over $("*").
Practice next
- Change .active to another li.
- Try $("#list li").first().
- Count with .length.
- Try $("[class=item]").
- Log .get(0) for the raw DOM node.
Remember
CSS selectors work in $(). Collections have .length. Be specific.
Find the row
Highlight the active menu item.
Outcome: Selector targets the right node.
Interview prep for this lesson
Practice these questions aloud after reading—each links to a full structured answer.
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