Ajax: Creating Web Pages with Asynchronous JavaScript and XML

Chapter 4. JavaScript I would like to point out that JavaScript has nothing to do with the Java programming language itself. Many people unfamiliar with JavaScript have a real problem with this, thinking that the word Java in JavaScript deno...

4.1. Data Types As with its ancestor, the C programming language of Kernighan and Ritchie, JavaScript supports a number of data types. Although the number isn't nearly as large as C, representatives of the basic data types are all present, and met...

4.2. Variables Unlike many other programming languages, in JavaScript, variables are not strongly typed, which means that what once contained a number could now be a string. This can sometimes cause some issues when developing on the client side; ...

4.3. Operators JavaScript has a number of operators that you might or might not be familiar with. These include the ever-present == (equals) and != (not equals), to which you have undoubtedly been exposed; there are a number of others. Although so...

4.4. Flow-Control Statements My first job straight out of college was working on an order-entry system that was developed by the elves at Bell Labs. Needless to say, I found myself in the Promised Land; although the salary was only alright, the to...

4.5. Functions Fromsome points of view, JavaScript functions are a little bit on the strange side when compared to other programming languages. This is because even though they are functions, they don't necessarily return a value. JavaScript funct...

4.6. Recursion Feel free to skip over this section if you're one of those developers with a fear of recursion; not only is this considered an advanced topic, but it can also literally cause headaches. If you should decide to read on, good for you!...

4.7. Constructors The capability to create custom objects is what separates modern programming languages from the programming languages of yore. Unfortunately, in JavaScript, this capability is one of those language features that is often either i...

4.8. Event Handling Bring up the subject of client-side events among a group of web developers, and the first (sometimes the only) one mentioned is the onclick event handler. Occasionally, someone will acknowledge the onmouseover and the onmouse...

4.9. Summary In this chapter, we started with the basics of JavaScript data types and variables; with a side trip to operators, we covered the basics and a little more. Our trek continued through the flow-control statements, the conditional ones ...