<?php
    /*
        返回当前元素的键名和键值，并将内部指针向前移动：
    */
    $people = array("Bill", "Steve", "Mark", "David");
    print_r(each($people));
    echo "<hr>";

    $people = array("Bill", "Steve", "Mark", "David");
    while (!!$a=each($people)) {
        echo $a[‘key‘].‘---‘.$a[‘value‘].‘<br/>‘;
    }
?>