Strict Standards: Only variables should be passed by reference in functions.php

Question

I'm a bit confused by the error I am getting.

The error is:

Strict Standards: Only variables should be passed by reference in functions.php

The line in reference is:

$action = array_pop($a = explode('?', $action)); // strip parameters

Answer 1

Try this:

$a= explode('?',$action);
$action = array_pop($a);

By the way, what is $action?