Once you’ve made an initial selection with jQuery, you can traverse deeper into what was just selected. Traversing can be broken down into three basic parts: parents, children, and siblings. jQuery has an abundance of easy-to-use methods for all these parts. Notice that each of these methods can optionally be passed string selectors, and some … Continue reading →

.index() is a method on jQuery objects that’s generally used to search for a given element within the jQuery object that it’s called on. This method has four different signatures with different semantics that can be confusing. This article covers details about how to understand the way .index() works with each signature. link .index() with … Continue reading →

jQuery offers several utility methods in the $ namespace. These methods are helpful for accomplishing routine programming tasks. For a complete reference on jQuery utility methods, visit the utilities documentation on api.jquery.com. Below are examples of a few of the utility methods: link $.trim()Removes leading and trailing whitespace: 1 2 // Returns “lots of extra … Continue reading →

Sometimes you want to make a piece of functionality available throughout your code. For example, perhaps you want a single method you can call on a jQuery selection that performs a series of operations on the selection. In this case, you may want to write a plugin. link How jQuery Works 101: jQuery Object MethodsBefore … Continue reading →

link Provide Public Access to Default Plugin SettingsAn improvement we can, and should, make to the code above is to expose the default plugin settings. This is important because it makes it very easy for plugin users to override/customize the plugin with minimal code. And this is where we begin to take advantage of the … Continue reading →

If you’re changing the CSS of more than 20 elements using .css(), consider adding a style tag to the page instead for a nearly 60% increase in speed. 1 2 3 4 5 6 // Fine for up to 20 elements, slow after that:$( “a.swedberg” ).css( “color”, “#0769ad” ); // Much faster:$( “<style type=\”text/css\”>a.swedberg { … Continue reading →

Use the source as your documentation. Bookmark the source code and refer to it often.

Selector optimization is less important than it used to be, as more browsers implement document.querySelectorAll() and the burden of selection shifts from jQuery to the browser. However, there are still some tips to keep in mind when selector performance becomes a bottleneck. link jQuery ExtensionsWhen possible, avoid selectors that include jQuery extensions. These extensions cannot … Continue reading →

jQuery won’t tell you if you’re trying to run a whole lot of code on an empty selection – it will proceed as though nothing’s wrong. It’s up to you to verify that your selection contains some elements. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 … Continue reading →

There’s often data about an element you want to store with the element. In plain JavaScript, you might do this by adding a property to the DOM element, but you’d have to deal with memory leaks in some browsers. jQuery offers a straightforward way to store data related to an element, and it manages the … Continue reading →