PHP 7: Real World Application Development

Chapter 3. Working with PHP Functions

In this chapter we will cover the following topics:

• Developing functions
• Hinting at data types
• Using return value data typing
• Using iterators
• Writing your own iterator using generators

Introduction

In this chapter we will consider recipes that take advantage of PHP's functional programming capabilities. Functional, or procedural, programming is the traditional way PHP code was written prior to the introduction of the first implementation of object-oriented programming (OOP) in PHP version 4. Functional programming is a programming paradigm—a style of building the structure and elements of computer programs—that treats computation as the evaluation of mathematical functions and avoids changing-state and mutable data. ...