Book Image

The Art of Modern PHP 8

By : Joseph Edmonds
5 (1)
Book Image

The Art of Modern PHP 8

5 (1)
By: Joseph Edmonds

Overview of this book

PHP has come a long way since its introduction. While the language has evolved with PHP 8, there are still a lot of websites running on a version of PHP that is no longer supported. If you are a PHP developer working with legacy PHP systems and want to discover the tenants of modern PHP, this is the book for you. The Art of Modern PHP 8 walks you through the latest PHP features and language concepts. The book helps you upgrade your knowledge of PHP programming and practices. Starting with object-oriented programming (OOP) in PHP and related language features, you'll work through modern programming techniques such as inheritance, understand how it contrasts with composition, and finally look at more advanced language features. You'll learn about the MVC pattern by developing your own MVC system and advance to understanding what a DI container does by building a toy DI container. The book gives you an overview of Composer and how to use it to create reusable PHP packages. You’ll also find techniques for deploying these packages to package libraries for other developers to explore. By the end of this PHP book, you'll have equipped yourself with modern server-side programming techniques using the latest versions of PHP.
Table of Contents (19 chapters)
Section 1 – PHP 8 OOP
Free Chapter
Chapter 1: Object-Oriented PHP
Section 2 – PHP Types
Chapter 5: Object Types, Interfaces, and Unions
Section 3 – Clean PHP 8 Patterns and Style
Section 4 – PHP 8 Composer Package Management (and PHP 8.1)
Section 5 – Bonus Section - PHP 8.1


That brings us to the end of Chapter 5, so here's a quick recap of what we have covered.

Firstly, we looked at the way objects and classes within an inheritance chain can be regarded as not only themselves but also all of their parents and interfaces.

We then had a look at the way comparison operators work when used with object instances and the difference between identity and equality.

Finally, we looked at the way PHP object variables are actually just references to a single instance and also looked at some different ways you can create a new instance.

In the next chapter, we are going to look at parameter and return types, which is where types gain most of their utility. We're also going to get our heads around covariance and contravariance – basically, the rules that define in what way you can tweak the parameter and return types when you are implementing or overriding methods from interfaces or parent classes, respectively.