type conversion - make switch use === comparison not == comparison In PHP

Question

Is there anyway to make it so that the following code still uses a switch and returns b not a? Thanks!

$var = 0;
switch($var) {
    case NULL : return 'a'; break;
    default : return 'b'; break;
}

Using if statements, of course, you'd do it like this:

$var = 0;
if($var === NULL) return 'a';
else return 'b';

But for more complex examples, this becomes verbose.

Answer 1

Sorry, you cannot use a === comparison in a switch statement, since according to the switch() documentation:

Note that switch/case does loose comparison.

This means you'll have to come up with a workaround. From the loose comparisons table, you could make use of the fact that NULL == "0" is false by type casting:

<?php
$var = 0;
switch((string)$var) 
{
    case "" : echo 'a'; break; // This tests for NULL or empty string   
    default : echo 'b'; break; // Everything else, including zero
}
// Output: 'b'
?>

Live Demo