Since PHP 8 the constant()
function throws an error instead of returning null
and generating an E_WARNING
when the given constant is not defined, and therefore I can't use the following code to set a variable anymore:
$foo = $SESSION['bar'] ?? constant("MY_CONSTANT") ?? "baz";
My obvious quick solution for this is changing that line to:
$foo = $SESSION['bar'] ?? (defined("MY_CONSTANT") ? constant("MY_CONSTANT") : "baz");
It honestly bothers me a little because I like how the first code is cleaner and do not force me to write ugly giant ternary sequences with a billion parentheses in case I want to add more constants to that ??
cascade. I also tried - hopeless because the (short) documentation around the null coalescing operator already stated that ??
was just a shortcut for isset()
in a ternary - the following:
$foo = $SESSION['bar'] ?? MY_CONSTANT ?? "baz";
But it didn't work - as expected. Another solution would be creating a function that returns null
when the constant is not defined, such as:
function defined_constant($constant) {
return (defined($constant) ? constant($constant) : null);
}
$foo = $SESSION['bar'] ?? defined_constant("MY_CONSTANT") ?? "baz";
I would like to know if there's any solution without creating new functions or changing the php.ini
file that would allow me use only ??
s as in that first line of code.
It is ok if the answer to my question is just a "no, there is no solution", but I'm intrigued and I can't find much stuff about this on the internet. PHP also seems to have just a few native functions around constants (three miscellaneous functions and the get_defined_constants()
?).
CodePudding user response:
true way is detect all undefined constants and define: defined('MY_CONSTANT') || define('MY_CONSTANT', 'baz');
and etc.
if you want save this trash constructions, then you can use something like this get_defined_constants()['MY_CONSTANT'] ?? 'baz'