Chapter 6. Working with Functions

Functions are at the heart of a well-organized script, making code easy to read and reuse. No large project would be manageable without them. Throughout this hour, we will investigate functions and demonstrate some of the ways in which they can save you from repetitive work. In this hour, you will learn

  • How to define and call functions

  • How to pass values to functions and receive values in return

  • How to call a function dynamically using a string stored in a variable

  • How to access global variables from within a function

  • How to give a function a “memory”

  • How to pass data to functions by reference

  • How to create anonymous functions

  • How to verify that a function exists before calling it

What Is a Function?

You can think of a ...

Get Sams Teach Yourself PHP, MySQL™ and Apache in 24 Hours now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.