jQuery — noConflict

The Problem

Other libraries may also use $:

// Conflict!
$.fn.somePlugin = function() {}; // jQuery
$.ajax({}); // Another library

$.noConflict()

Releases the $ alias:

$.noConflict();
// $ is no longer jQuery
var jq = jQuery; // Use jQuery instead
jq("p").text("Hello");

Using an Alias

var $j = $.noConflict();
$j("p").text("Hello");

IIFE Pattern

(function($) {
    // $ is jQuery inside here
    $("p").text("Hello");
})(jQuery);

Multiple Libraries

// Prototype
$.noConflict();

// jQuery accessible as jq
var jq = $.noConflict(true); // Also removes jQuery from window

When to Use noConflict

• WordPress sites (uses Prototype/MooTools)
• Projects mixing jQuery and other libraries
• Legacy codebases

Mini Practice

1. Use $.noConflict() and test
2. Create an alias with var
3. Wrap code in an IIFE with $ parameter
4. Verify other libraries work alongside jQuery

Up Next

Continue with Plugins — extending jQuery with plugins.