Q:

declaring user function with default non-value parameters

At declaring user function with default non-value parameters, what way is better, define parameters as false or as NULL ?
that is,  what is better, this
 function func ($param = false) {

 }

or this
 function func ($param = NULL) {

 }

?

A:

This would be better:
function func ($param = NULL) {

}

A "default non-value" parameter should be NULL, not false. False is a value. If you intend to test the parameter for its value or perform any operation on/with it, I would go with false.

