分配给逗号数组的自定义键逗号数组

我有以下数组：

$doc_id = (3,5,4,6)
$requirement2 = (2,0,0,1)

我正试图使用以下代码使$doc_id成为$requirement2的关键元素：

<?php
include "../includes/auth.php";
include "../includes/header.php";

$jat_id = intval($_GET['id']);
$div_id = intval($_GET['div_id']);

    $order = "SELECT * FROM document_assoc WHERE jat_id = '$jat_id'";
    $result = mysql_query($order);
    $row = mysql_fetch_array($result);
    $doc_id3 = $row['doc_id'];
    $doc_id = explode(",", $doc_id3);
    $requirement = $row['requirement'];
    $requirement2 = explode(",", $requirement);
    foreach ($doc_id as $doc_id4) {
    $requirement3 = array($doc_id4=>$requirement3);
    foreach ($requirement2 as $requirement3) {
    $requirement3 = array($doc_id4=>$requirement3);
    print_r ($requirement3);
    }}
include "../includes/footer.php";
?>

然而，我在print_r（）上收到以下内容：

Array ( [3] => 2 ) Array ( [3] => 0 ) Array ( [3] => 0 ) Array ( [3] => 1 ) Array ( [5] => 2 ) Array ( [5] => 0 ) Array ( [5] => 0 ) Array ( [5] => 1 ) Array ( [4] => 2 ) Array ( [4] => 0 ) Array ( [4] => 0 ) Array ( [4] => 1 ) Array ( [6] => 2 ) Array ( [6] => 0 ) Array ( [6] => 0 ) Array ( [6] => 1 ) 

这是我迄今为止最接近的一次。但显然还是错了。

从我读到的内容来看，我需要它看起来像这样：

Array ( [3] => 2 [5] => 0 [4] => 0 [6] => 1 ) 

这样以后我就可以用$requirement3[$doc_id]来称呼它了。（调用$doc_id时，它将是一个不同于在此数组键中设置它的变量源）。

如果有人能帮助解释我在2个foreach陈述中做错了什么，我将非常感谢你能更好地理解我。

亲切问候