PHP and MySQL Web Development, Third Edition

Chapter 25. Debugging

This chapter deals with debugging PHP scripts. If you have worked through some of the examples in the book or used PHP before, you will probably already have developed some debugging skills and techniques of your own. As your projects get more complex, debugging can become more difficult. Although your skills improve, the errors are more likely to involve multiple files or interactions between code written by multiple people.

Key topics covered in this chapter include

• Programming error types

  • Syntax errors

  • Runtime errors

  • Logic errors

• Error messages

• Error levels

• Triggering your own errors

• Handling errors gracefully

Programming Errors

Regardless of which language you are using, there are three general types of program errors:

• Syntax errors ...