数组长度相同，怎么把一个数组的键名变成第二个数组的键值

数组长度相同，如何把一个数组的键名变成第二个数组的键值。
比如我有$aa....$bb

$aa=Array ("0" =>"cd","1" =>"udd","2"=>"dsd");
$bb=Array ( "0" => 13ds,"1" =>"tdfestsdfa1","2" => "1122sdfdsasdf33abc") ;
把$aa数组的键名变成第二个数组$bb的键值。

如何形成如下数组￥cc。

$cc=Array ( "cd" => 13ds,"udd" =>"tdfestsdfa1","dsd" => "1122sdfdsasdf33abc") ;

请高人指点。
------解决思路----------------------

$aa = Array("0" => "cd", "1" => "udd","2" => "dsd");<br />$bb = Array("0" => "13ds", "1" => "tdfestsdfa1", "2" => "1122sdfdsasdf33abc");<br />$cc = array_combine($aa, $bb);<br />print_r($cc);

$aa = Array("0" => "cd", "1" => "udd","2" => "dsd");<br />$bb = Array("0" => "13ds", "1" => "tdfestsdfa1", "2" => "1122sdfdsasdf33abc");<br />$cc = array_combine($aa, $bb);<br />print_r($cc);