Re: Function parameter passed by reference with default value to null

2009/7/6 Lupus Michaelis <mickael+php@lupusmic.org>: >  I'm happy PHP raises an error on foo(null) ; >  I'm in trouble when foo() doesn't. > >  The actual question is : why PHP doesn't raise an error ? This functionality (default values for passed-by-reference parameters) was added in PHP5. The problem is that you can't pass literals by reference (which makes sense): function f(&$a) {} f(45); // error But default values must be literals (which also makes sense): function f($a = $_POST) {} // error So there's some serious impedance mismatch going on there to make both features to work together. Just think of the default value as "something I can overwrite", eg: function f(&$a = 45) { $a = 99; } So it doesn't really matter if it starts off as 45, 'Hello World' or null... it's going to get thrown away at the end of the function's lifetime, anyway.