Learning PHP, MySQL & JavaScript, 4th Edition

Chapter 21. Introduction to jQuery

Powerful and flexible as JavaScript is, with a plethora of built-in functions, you still need additional layers of code for simple things that cannot be achieved natively or with CSS, such as animations, event handling, and Ajax.

What’s more, as a consequence of the various browser wars over the years, frustrating and annoying browser incompatibilities have come and gone, rearing their heads at different times on different platforms and programs.

As a result, ensuring your web pages look the same on all devices can sometimes be achieved only through tedious JavaScript code that accounts for all the discrepancies across the range of browsers and versions released over recent years. In a word—nightmare.

As I write (in 2014), we seem to be in the midst of a quieter spell, because Microsoft’s Internet Explorer has caught up with the standards in many (but not all) areas, Opera has opted to use WebKit (the same technology used by Google) as the core of its browser, and Apple has bowed out of the PC browser marketplace.

Nevertheless, legacy inconsistencies remain, and plenty of people use older browsers. Plus there’s still the issue of needing to write a substantial amount of JavaScript when you want to create anything more than basic special effects.

To fill these gaps, a number of libraries of functions to minimize the differences between browsers have been developed, many of which also provide easy hooks into the DOM (Document Object Model), and ...