Default

default is a PHP keyword, used with switch() and match() structures. It represents any case that was not already considered.

<?php

switch ($i) {
    case 0:
        echo "i equals 0";
        break;
    case 1:
        echo "i equals 1";
        break;
    default 2:
        echo "i is not 0 nor 1";
        break;
}

?>

Documentation

Related : Switch, Match, Case