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

Developing functions


The most difficult aspect is deciding how to break up programming logic into functions. The mechanics of developing a function in PHP, on the other hand, are quite easy. Just use the function keyword, give it a name, and follow it with parentheses.

How to do it...

  1. The code itself goes inside curly braces as follows:

    function someName ($parameter)
    { 
      $result = 'INIT';
      // one or more statements which do something
      // to affect $result
      $result .= ' and also ' . $parameter;
      return $result; 
    }
  2. You can define one or more parameters. To make one of them optional, simply assign a default value. If you are not sure what default value to assign, use NULL:

    function someOtherName ($requiredParam, $optionalParam = NULL)
      { 
        $result = 0;
        $result += $requiredParam;
        $result += $optionalParam ?? 0;
        return $result; 
      }

    Note

    You cannot redefine functions. The only exception is when duplicate functions are defined in separate namespaces. This definition would generate...