Fanshawe College, INFO-5094: LAMP 2, Project 1 - IteratorMode examples of using Bitwise operators

gistfile1.php

<?php

class IteratorMode
{
    const KEEP      = 1;
    const DELETE    = 2;
    const FIFO      = 4;
    const LIFO      = 8;
    
    public static function isKeep($mode)
    {
        return 1 == ($mode & self::KEEP);
    }
    
    public static function isFifo($mode)
    {
        return 4 == ($mode & self::FIFO);
    }
}

// Example usage ...
$keep_and_fifo = IteratorMode::KEEP | IteratorMode::FIFO;
if (IteratorMode::isKeep($keep_and_fifo)) {
    // Yay! Our iterator will not delete nodes as we traverse.
}

$xored_keep_and_fifo = IteratorMode::DELETE ^ IteratorMode::FIFO;
if (IteratorMode::isFifo($xored_keep_and_fifo)) {
    // Awesome! We are moving forward, first-in, first-out
}

Note: The IteratorMode::DELETE ^ IteratorMode::FIFO could also be an OR instead of XOR.