将一维或多维的数组连接成一个字符串的php代码

/*
* ――――――――――――――――-
* @file : 5.php
* @function : arr2str
* @copyright : 2002-2009 Xingmo Inc
* @author : Fanglor <fanglor#163.com>
* @date : 2010-06-25
* @update :
* ――――――――――――――――-
*/
<?php
$fruits = array (
"fruits" => array("a" => "orange", "b" => "banana", "c" => "apple"),
"numbers" => array(1, 2, 3, 4, 5, 6),
"holes" => array("first", 5 => "second", "third")
);
$arr1 = array(1, 2, 3, 4, 5, 6=>'fanglor');
function arr2str ($arr)
{
static $res_arr = array();
if (is_array ($arr))
{
foreach ($arr as $key => $val )
{
if (is_array($val))
{
arr2str ($val);
}
else
{
$res_arr[] = $val;
}
}
}
elseif (is_string ($arr))
{
$res_arr[] = $arr;
}
return implode(',',$res_arr);
}
$str = arr2str ($arr1);
print_r ($str);
?>