Book Image

PHP 7 Programming Cookbook

By : Doug Bierer
Book Image

PHP 7 Programming Cookbook

By: Doug Bierer

Overview of this book

PHP 7 comes with a myriad of new features and great tools to optimize your code and make your code perform faster than in previous versions. Most importantly, it allows you to maintain high traffic on your websites with low-cost hardware and servers through a multithreading web server. This book demonstrates intermediate to advanced PHP techniques with a focus on PHP 7. Each recipe is designed to solve practical, real-world problems faced by PHP developers like yourself every day. We also cover new ways of writing PHP code made possible only in version 7. In addition, we discuss backward-compatibility breaks and give you plenty of guidance on when and where PHP 5 code needs to be changed to produce the correct results when running under PHP 7. This book also incorporates the latest PHP 7.x features. By the end of the book, you will be equipped with the tools and skills required to deliver efficient applications for your websites and enterprises.
Table of Contents (22 chapters)
PHP 7 Programming Cookbook
Credits
Foreword
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Implementing a stack


A stack is a simple algorithm normally implemented as Last In First Out (LIFO). Think of a stack of books sitting on a library table. When the librarian goes to restore the books to their place, the topmost book is processed first, and so on in order, until the book at the bottom of the stack has been replaced. The topmost book was the last one to be placed on the stack, thus last in first out.

In programming terms, a stack is used to temporarily store information. The retrieval order facilitates retrieving the most recent item first.

How to do it...

  1. First we define a class, Application\Generic\Stack. The core logic is encapsulated in an SPL class, SplStack:

    namespace Application\Generic;
    use SplStack;
    class Stack
    {
      // code
    }
  2. Next we define a property to represent the stack, and set up an SplStack instance:

    protected $stack;
    public function __construct()
    {
      $this->stack = new SplStack();
    }
  3. After that we define methods to add and remove from the stack, the classic push...