Book Image

Learning jQuery - Fourth Edition - Fourth Edition

Book Image

Learning jQuery - Fourth Edition - Fourth Edition

Overview of this book

To build interesting, interactive sites, developers are turning to JavaScript libraries such as jQuery to automate common tasks and simplify complicated ones. Because many web developers have more experience with HTML and CSS than with JavaScript, the library's design lends itself to a quick start for designers with little programming experience. Experienced programmers will also be aided by its conceptual consistency. LearningjQuery - Fourth Edition is revised and updated version of jQuery. You will learn the basics of jQuery for adding interactions and animations to your pages. Even if previous attempts at writing JavaScript have left you baffled, this book will guide you past the pitfalls associated with AJAX, events, effects, and advanced JavaScript language features. Starting with an introduction to jQuery, you will first be shown how to write a functioning jQuery program in just three lines of code. Learn how to add impact to your actions through a set of simple visual effects and to create, copy, reassemble, and embellish content using jQuery's DOM modification methods. The book will take you through many detailed, real-world examples, and even equip you to extend the jQuery library itself with your own plug-ins.
Table of Contents (24 chapters)
Learning jQuery Fourth Edition
About the Authors
About the Reviewers

Appendix A. JavaScript Closures

Throughout this book, we have seen many jQuery methods that take functions as parameters. Our examples have thus created, called, and passed around functions time and again. While usually we can do this with only a cursory understanding of the inner JavaScript mechanics at work, at times side effects of our actions can seem strange if we do not have knowledge of the language's features. In this appendix, we will cover:

  • JavaScript's ability to define functions within other functions

  • Ways in which function objects can be passed around

  • The scope of variables defined inside and outside functions

  • Common problems caused by variable scoping and closures

  • How jQuery constructs interact with function definitions

  • Memory issues that can be caused by the interactions between functions