Why use native define?

Why do you use the native define() to define global constants? You're not using them like you should anyway, due to the var_export, so why not do it right?

<?php

class Const {
$constants = array();
static function set($name, $var) {
self::$constants[$name] = $var; // yup, that easy
}
static get($name, $alt = null) {
return isset(self::$constants[$name]) ? self::$constants[$name] : $alt;
}
}

?>

The whole point of this class is to be able to save an array into a _constant_ (hence define() is used).

You also don't want to return a null because, technically, 'null' could be a value of a property in an array.

Can't edit messages here, so I elaborate in another message:

I should've said above: "You also don't want to return a null by default when a property is not found because, technically, 'null' could be the value of a property in an array."