Implementing permissions in PHP

Question

I've tried to do this several times with no luck. After reading this post, it made me interested in doing this again. So can anyone tell me why the following doesn't work?

<?php

$guest = 1;
$editor = 2;
$admin = 4;

$user = $editor;

if( $user == ($editor | $admin) ) {
    echo "Test";    
}

?>

Answer 1

Use the bitwise OR operator (|) to set bits, use the AND operator (&) to check bits. Your code should look like this:

<?php

    $guest = 1;
    $editor = 2;
    $admin = 4;

    $user = $editor;

    if( $user & ($editor | $admin) ) {
        echo "Test";    
    }

?>

If you don't understand binary and exactly what the bitwise operators do, you should go learn it. You'll understand how to do this much better.