“休息2”是什么意思？

我总是使用和看到只带有“break”的例子。这是什么意思：

 <?php 
    while ($flavor = "chocolate") { 
      switch ($flavor) { 
        case "strawberry"; 
            echo "Strawberry is stock!"; 
            break 2;    // Exits the switch and the while 
        case "vanilla"; 
            echo "Vanilla is in stock!"; 
            break 2;   // Exits the switch and the while 
        case "chocolate"; 
            echo "Chocolate is in stock!"; 
            break 2;    // Exits the switch and the while 
        default;     
            echo "Sorry $flavor is not in stock"; 
            break 2;    // Exits the switch and the while 
      } 
    } 
    ?>

“break”语句是否有更多可用选项？

来自PHP 文档上break http://php.net/manual/en/control-structures.break.php:

Break 接受一个可选的数字参数，该参数告诉它要打破多少个嵌套的封闭结构。

正如评论中指出的，它打破了切换和同时.

下面的例子将打破所有foreach loops:

foreach (...) {
  foreach (..) {
    foreach (...) {
      if ($condition) {
        break 3;
      }
    }
  }
}