Book Image

Learning PHP 7

By : Antonio L Zapata (GBP)
Book Image

Learning PHP 7

By: Antonio L Zapata (GBP)

Overview of this book

PHP is a great language for building web applications. It is essentially a server-side scripting language that is also used for general purpose programming. PHP 7 is the latest version with a host of new features, and it provides major backwards-compatibility breaks. This book begins with the fundamentals of PHP programming by covering the basic concepts such as variables, functions, class, and objects. You will set up PHP server on your machine and learn to read and write procedural PHP code. After getting an understanding of OOP as a paradigm, you will execute MySQL queries on your database. Moving on, you will find out how to use MVC to create applications from scratch and add tests. Then, you will build REST APIs and perform behavioral tests on your applications. By the end of the book, you will have the skills required to read and write files, debug, test, and work with MySQL.
Table of Contents (17 chapters)
Learning PHP 7
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Anonymous functions


Anonymous functions, or lambda functions, are functions without a name. As they do not have a name, in order to be able to invoke them, we need to store them as variables. It might be strange at the beginning, but the idea is quite simple. At this point of time, we do not really need any anonymous function, so let's just add the code into init.php, and then remove it:

$addTaxes = function (array &$book, $index, $percentage) {
    $book['price'] += round($percentage * $book['price'], 2);
};

This preceding anonymous function gets assigned to the variable $addTaxes. It expects three arguments: $book (an array as a reference), $index (not used), and $percentage. The function adds taxes to the price key of the book, rounded to 2 decimal places (round is a native PHP function). Do not mind the argument $index, it is not used in this function, but forced by how we will use it, as you will see.

You could instantiate a list of books as an array, iterate them, and then call this...