The define() function defines a constant.
Syntax
define(const_name,value,case_insensitive)
Parameters
const_name − The name of the constant.
value − The value of the constant.
case_insensitive − The constant name should be case-insensitive.
Return
The define() function returns true on success or false on failure.
Example
The following is an example that defines a constant.
<?php
define("message","This is it!");
echo constant("message");
?>Ouptut
The following is the output.
This is it!