JavaScript and JQuery: Interactive Front-End Web Development

7

JQUERY

jQuery offers a simple way to achieve a variety of common JavaScript tasks quickly and consistently, across all major browsers and without any fallback code needed.

SELECT ELEMENTS

It is simpler to access elements using jQuery's CSS-style selectors than it is using DOM queries. The selectors are also more powerful and flexible.

PERFORM TASKS

jQuery's methods let you update the DOM tree, animate elements into and out of view, and loop through a set of elements, all in one line of code.

HANDLE EVENTS

jQuery includes methods that allow you to attach event listeners to selected elements without having to write any fallback code to support older browsers.

This chapter assumes that you have read the book up to this point or are familiar with the basics of JavaScript. As you will see, jQuery is powerful when combined with traditional JavaScript techniques, but you need to understand JavaScript to make full use of jQuery.

WHAT IS JQUERY?

jQuery is a JavaScript file that you include in your web pages. It lets you find elements using CSS-style selectors and then do something with the elements using jQuery methods.

1: FIND ELEMENTS USING CSS-STYLE SELECTORS

A function called jQuery() lets you find one or more elements in the page. It creates an object called jQuery which holds references to those elements. $() is often used as a shorthand to save typing jQuery(), as shown here.