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

Object type inheritance

Each class and interface is a type. There are also various types that PHP has built-in and that your class or interface might also incorporate.

Any object is an instance of a specific class – the class that it was created from using the new keyword. This is the most obvious type for the object. After that, it is the class's parent class (if it has one), and then its grandparent class (again if it has one)… all the way up to the grandest-parentiest class at the top of the hierarchical chain.

Further to this, each class is also every interface it implements, and the parent and grandparent (and so on) interfaces of those interfaces, again all the way to the top. Remember, a single class can implement multiple interfaces and those interfaces can all extend further interfaces.

As you can imagine, this can get confusing, and it's one reason why massive inheritance chains can be a bad thing when it comes to having comprehensible code...