Can I use variable functions with language constructs?

Question

This question here kinda address the issue. In my case I would like to call a function like empty() or is_int(). For example:

<?php

    $foo = 'empty';
    $test = NULL;
    $foo($test);

This question is not a duplicate of:

How to call PHP function from string stored in a Variable

My question addresses a native PHP function not a user made function.

It isn't a duplicate. My question addresses a native PHP function not a user made function. — Francisco Luz, Jul 30 '15 at 13:22
afaik this is not really possible. Best way to do would be to put the PHP functions into your own methods and call it via call_user_func — ThomasVdBerge, Jul 30 '15 at 13:25

score 3 · Accepted Answer · answered Jul 30 '15 at 13:27

Variable function doesn't work with language constructs as you can read in the manual:

Variable functions won't work with language constructs such as echo, print, unset(), isset(), empty(), include, require and the like. Utilize wrapper functions to make use of any of these constructs as variable functions.

Can I use variable functions with language constructs?

1 Answers1