# PHP Functions

A function is a piece of code that can be used repeatedly in a PHP program. A function is mainly of two types:

• Built in Functions; which are already defined in PHP Library.
• User Defined Functions; which are created and defined by users.

Syntax:

function functionName(parameters) { code to be executed; }

Rules for using Functions:

• Name of a function are case-insensitive.
• A function starts with an opening curly brace ( { ) and ends with a closing curly brace ( } ).
• Arguments are the variables, inside the parentheses, after the function name which is used to pass informations to functions.
• For multiple arguments, comma should be used for separation.
• Default argument value can also be specified in a function. If no argument is specified, the function will take the default argument.
• Functions can also be used to return value.

Example

<!DOCTYPE html> <html> <body>   <?php function writeMsg() { echo "My First Program using Function!"; }   writeMsg(); ?>   </body> </html>

Output

My First Program using Function!