Say I have a class with a constant in it. I also have a variable in
that class that I would like to set to that constant as the
initialization value. Why doesn't the following work?

class Square
{
const DEFAULT_SIZE=5;
var $size=self::DEF AULT_SIZE; // how do i set $size to DEFAULT_SIZE?
}

$r= new Square();

Errors are:

PHP Fatal error: Cannot access self:: when...