In another part of their series of excerpts from the Zend PHP Certification Guide (from Zend), DevShed has posted this article talking about debugging and performance issues and methods.

Making mistakes is human, and so is fixing them. In your day-to-day programming adventures, it's inevitable to introduce bugs in your PHP code, especially when you're writing very complex applications with tens of thousands of lines of code spread across tens of files.

In this article they look at things like flattening if statements, spplitting single commands across multiple lines, and the difference between =, ==, and ===.