PHP for Absolute Beginners

2.7. User-Defined

Perhaps the most powerful feature of PHP is the ability to define and execute functions from within your code. A function is a named block of code that you declare within your scripts that you can call at a later time. Functions can accept any number of arguments and can return a value using the return statement.

The basic format of a function requires that you first identify the function using the function reserved word in front of a string that serves as the function's name. This string can contain any alphanumeric characters and underscores, but it must not start with a number. You enclose any arguments you want in parentheses after the function name. Note that you still must include the parentheses even if the function ...