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

Hinting at data types


In many cases when developing functions, you might reuse the same library of functions in other projects. Also, if you work with a team, your code might be used by other developers. In order to control the use of your code, it might be appropriate to make use of a type hint. This involves specifying the data type your function expects for that particular parameter.

How to do it...

  1. Parameters in functions can be prefixed by a type hint. The following type hints are available in both PHP 5 and PHP 7:

    • Array

    • Class

    • Callable

  2. If a call to the function is made, and the wrong parameter type is passed, a TypeError is thrown. The following example requires an array, an instance of DateTime, and an anonymous function:

    function someTypeHint(Array $a, DateTime $t, Callable $c)
    {
      $message = '';
      $message .= 'Array Count: ' . count($a) . PHP_EOL;
      $message .= 'Date: ' . $t->format('Y-m-d') . PHP_EOL;
      $message .= 'Callable Return: ' . $c() . PHP_EOL;
      return $message;
    }

    Tip

    You don...