Book Image

Mastering PHP 7

By : Branko Ajzele
Book Image

Mastering PHP 7

By: Branko Ajzele

Overview of this book

PHP is a server-side scripting language that is widely used for web development. With this book, you will get a deep understanding of the advanced programming concepts in PHP and how to apply it practically The book starts by unveiling the new features of PHP 7 and walks you through several important standards set by PHP Framework Interop Group (PHP-FIG). You’ll see, in detail, the working of all magic methods, and the importance of effective PHP OOP concepts, which will enable you to write effective PHP code. You will find out how to implement design patterns and resolve dependencies to make your code base more elegant and readable. You will also build web services alongside microservices architecture, interact with databases, and work around third-party packages to enrich applications. This book delves into the details of PHP performance optimization. You will learn about serverless architecture and the reactive programming paradigm that found its way in the PHP ecosystem. The book also explores the best ways of testing your code, debugging, tracing, profiling, and deploying your PHP application. By the end of the book, you will be able to create readable, reliable, and robust applications in PHP to meet modern day requirements in the software industry.
Table of Contents (24 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Customer Feedback
Preface
16
Debugging, Tracing, and Profiling

Using __destruct()


Alongside the constructor, the destructor is a common feature of the OO language. The __destruct() magic method represents this concept. The method gets triggered as soon as there are no other references to a particular object. This can happen either when PHP decides to explicitly free the object, or when we force it using the unset()  language construct.

As with constructors, parent destructors don't get called implicitly by PHP. In order to run a parent destructor, we need to explicitly call parent::__destruct(). Furthermore, the child class inherits the parent's destructor if it does not implement one for itself.

Let's say we have a following simple User class:

<?php

class User
{
   public function __destruct()
   {
      echo '__destruct';
   }
}

With the User class in place, let's go ahead and look through instance creation examples:

echo 'A';
new User();
echo 'B';

// outputs "A__destructB"

The new User(); expression here instantiates an instance of the User class...