居然还有这种操作 -- 学到老活到老系列

break#

<?php
$arr = array('one', 'two', 'three', 'four', 'stop', 'five');
while (list(, $val) = each($arr)) {
    if ($val == 'stop') {
        break;    /* You could also write 'break 1;' here. */
    }
    echo "$val<br />\n";   
}

/* Using the optional argument. */

$i = 0;
while (++$i) {
    switch ($i) {
    case 5:
        echo "At 5<br />\n";
        break 1;  /* Exit only the switch. */
    case 10:
        echo "At 10; quitting<br />\n";
        break 2;  /* Exit the switch and the while. */
    default:
        break;
    }
}
?>

whaaaaaaaat？还有这种操作？再来看看手册

看来是自己out了。

Version	Description
5.4.0	break 0; is no longer valid. In previous versions it was interpreted the same as break 1;
5.4.0	Removed the ability to pass in variables (e.g., $num = 2; break $num;) as the numerical argument.