Today, JavaScript is used in 89.9% of all websites, including the most heavily-trafficked sites like Google, Facebook, YouTube, and Amazon. That is why every web developer should know how to use JavaScript. The problem is that JavaScript is surprisingly difficult to learn, not only for programming novices but also for experienced programmers. But now, Murachs JavaScript makes it easier than ever to become an accomplished JavaScript programmer. To make that possible, section 1 of this book presents a six-chapter course in JavaScript that gets you off to a great start. This section works for programming novices as well as experienced programmers because it lets you set your own pace. When you finish this section, you will be able to write, test and debug JavaScript applications of your own. Then, section 2 builds on that base by presenting the additional skills that every JavaScript programmer must have. That includes working with arrays and web storage, creating and using your own object types in object-oriented applications, using regular expressions for data validation, and much more. For many developers, sections 1 and 2 will be all that they need to know. But for those who want to move on to the expert level, section 3 presents the skills that will get you there. That includes skills like how to bulletproof your applications by using closures, namespaces, and modules; how to make your functions more useful by using callbacks; and how to use JSON to transmit and store data. Then, the last chapter in this section introduces you to jQuery and shows you how it can make your JavaScript code even better.