<?php
function swap(&$a, &$b) {
$a = $a ^ $b;
$b = $a ^ $b;
$a = $a ^ $b;
}
$a = "One - 1";
$b = "Two - 2!!!";
echo $a . $b . "\n"; // One - 1Two - 2!!!
swap($a, $b);
echo $a . $b; // Two - 2One - 1
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