Quote from the manual:
http://www.php.net/manual/en/functions.arguments.php#functions.arguments.default
A function may define C++-style default
values for scalar arguments as follows:
function makecoffee ($type = "cappuccino")
{
return "Making a cup of $type.\n";
}
echo makecoffee ();
echo makecoffee ("espresso");
The output from the above snippet is:
Making a cup of cappuccino.
Making a cup of espresso.
The default value must be a constant expression, not (for example) a variable or class member.
So, I guess, the answer is "NO".