PHP常用的数组操作函数-指针的移动

$transport = array('foot', 'bike', 'car', 'plane');
$mode = current($transport); // $mode = 'foot';
$mode = next($transport);    // $mode = 'bike';
$mode = next($transport);    // $mode = 'car';
$mode = prev($transport);    // $mode = 'bike';
$mode = end($transport);     // $mode = 'plane';
// 重置指针，重新指向第一个元素
reset($transport);
$mode = current($transport); // $mode = 'foot';