PHP has a set of built-in functions.
Custom functions
You can — and should — also write your own custom functions.
Functions provide a system for organizing your code. A function is a container for some code, which will be available for use by other code.
Functions make code modular: easier to understand, more useful, more reusable.
A custom function begins with a name you invent for your function. Pick function names that are description The name must not be a PHP reserved keyword.
Syntax
function functionName()
{
code to be executed;
}
PHP function guidelines:
- Give the function a name that reflects what the function does
- The function name can start with a letter or underscore (not a number)
