`break`

break 结束当前 for，foreach，while，do..while 或者 switch 结构的执行。

break 可以接受一个可选的数字参数来决定跳出几重循环。


<?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;
    }
}
?>