Professional, JavaScript® for Web Developers, Second Edition

Appendix B. JavaScript Tools

Writing JavaScript is a lot like writing in any other programming language except that, until recently, there were fewer tools. Since 2000, the number of tools available for JavaScript developers has exploded, making it much easier to locate problems, optimize, and deploy JavaScript-based solutions. Some of the tools are designed to be used from JavaScript, whereas others can be run outside the browser. This appendix provides an overview of some of these tools, as well as additional resources for more information.

Debuggers

At one time, debugging JavaScript meant including a series of alerts to follow code execution through an application. That time is long past since each of the four major browsers—Internet Explorer (IE), Firefox, Safari, and Opera—have at least one JavaScript debugger available. Some of the debuggers are available for free and others require purchasing a license, but all of them give you greater insight into how your JavaScript code is functioning.

Microsoft Script Debugger

This is an old debugger designed for use with IE 6.0 and earlier, though it works with later versions. The Microsoft Script Debugger is a free tool that provides basic debugging functionality, including breakpoints, stepping through code, and call-stack information. This utility is very basic and, although it works, is very far behind the times when it comes to JavaScript debuggers.

• Price: Free

• Browsers: IE 6.0 and earlier

• Web site: http://www.microsoft.com/Downloads/details.aspx?familyid=2F465BE0-94FD-4569-B3C4-DFFDF19CCD99 ...