jQuery·jQuery from selection to migration

Plugins and utilities

Use $.extend, $.each and data attributes without over-engineering.

Beginner 12 min read Lesson 8 of 300 Challenge included

What you will be able to do

Plugins should return the collection.
Use $.extend for defaults and deep copies.
Store instance data with .data().
Clean up handlers and timers on destroy.

In plain English

jQuery plugins extend $.fn and are chained like built-in methods. Utilities such as $.extend copy objects and $.each iterates. Prefer small, single-purpose plugins and avoid global state.

plugin.jsJavaScript

$.fn.highlight = function (options) {
  const settings = $.extend({ color: '#ffe08a' }, options)
  return this.each(function () {
    $(this).css('background-color', settings.color)
  })
}

$('.row').highlight({ color: '#eef6ff' })

Your turn

Return the collection

Easy

Make a plugin return this.each(...).

JAVASCRIPT · starter

function () { }

Check your understanding before moving on.

Knowledge checkQuestion 1

What should a jQuery plugin return to support chaining?

Select an answer to continue

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Lesson 8 of 300 · 0% of course