PHP and Algorithmic Thinking for the Complete Beginner

Chapter 36 User-Defined Subprograms

36.1 Subprograms that Return a Value

In PHP and many other computer languages, a subprogram that returns a value is called a function. Τhere are two categories of functions in PHP. There are the built-in functions, such as abs(), sqrt(), and there are the user-defined functions, those that you can personally write and use in your own programs.

The general form of a PHP function that returns a value is shown here.

function name([$arg1, $arg2, $arg3, …]) {

A statement or block of statements

return value;

}

where

►name is the name of the function.

►$arg1, $arg2, $arg3, … is a list of arguments (variables, arrays etc.) used to pass values from the caller to the function. There can be as many arguments as you ...