Why Return this in a jQuery Plugin?

When developing a jQuery plugin, returning this is a fundamental best practice that preserves jQuery’s signature method chaining capability. Without returning the jQuery object context, developers consuming your plugin cannot execute multiple commands sequentially on the same selector, breaking the expected behavior of the library. This article explains the technical mechanics of returning this, how it interacts with element iteration, and why it is critical for writing robust jQuery extensions.

Enabling Method Chaining

The defining feature of jQuery is method chaining—the ability to run multiple methods on the same set of elements in a single statement:

$('#element').myPlugin().addClass('highlight').fadeIn();

For chaining to work, every method in the sequence must return a jQuery object. If your plugin executes its logic but does not return anything, JavaScript implicitly returns undefined. As a result, any subsequent method called on that chain (like .addClass() or .fadeIn()) will throw a TypeError: Cannot read properties of undefined. Returning this ensures the original jQuery selection passes down the chain uninterrupted.

Understanding this Inside Plugin Scope

Inside the immediate scope of a jQuery plugin function, this already refers to the jQuery collection wrapper, not a raw DOM node:

$.fn.myPlugin = function() {
    // 'this' is already a jQuery object (equivalent to $('#element'))
    return this; 
};

Because this is already the jQuery object, calling $(this) in the outer scope of the plugin is redundant. Returning this directly yields the exact collection that the user initially targeted.

Handling Multiple Elements with this.each()

Most jQuery selectors match multiple DOM nodes. To perform actions on each individual element while maintaining chainability, plugins typically wrap their logic inside this.each():

$.fn.highlightText = function(color) {
    return this.each(function() {
        // Inside this callback, 'this' refers to an individual DOM element
        $(this).css('background-color', color);
    });
};

The .each() method iterates through every element in the collection and automatically returns the original jQuery object (this). Prepending return to this.each(...) accomplishes two essential tasks at once: it processes every matched element and seamlessly returns the collection for future chaining.

When Not to Return this

The only exception to returning this occurs when the plugin is intentionally designed to retrieve data rather than manipulate elements. If your plugin functions as a getter—such as returning a computed coordinate, a boolean state, or an aggregated string value—it must return that specific data value instead. However, for any plugin that performs UI manipulations, binds events, or changes element state, returning this is strictly required.