php如何去除多维数组重复值

<?php
$input = array("a" => "green","", "red","b" => "green", "","blue", "red","c" => "witer","hello","witer");
//$result = array_unique($input); //去除重复元素
$result = a_array_unique($input); //只留下单一元素
foreach($result as $aa)
{
echo $aa."<br />";
}
function multi_unique($array) {
 foreach ($array as $k=>$na)
 $new[$k] = serialize($na);
 $uniq = array_unique($new);
 foreach($uniq as $k=>$ser)
 $new1[$k] = unserialize($ser);
 return ($new1);
}
function a_array_unique($array)//写的比较好
{
 $out = array();
 foreach ($array as $key=>$value) {
 if (!in_array($value, $out))
{
 $out[$key] = $value;
 }
 }
 return $out;
} 
?>

function unique_arr($array2D,$stkeep=false,$ndformat=true)
{
 // 判断是否保留一级数组键 (一级数组键可以为非数字)
 if($stkeep) $stArr = array_keys($array2D);
 // 判断是否保留二级数组键 (所有二级数组键必须相同)
 if($ndformat) $ndArr = array_keys(end($array2D));
 //降维,也可以用implode,将一维数组转换为用逗号连接的字符串
 foreach ($array2D as $v){
 $v = join(",",$v); 
 $temp[] = $v;
 }
 //去掉重复的字符串,也就是重复的一维数组
 $temp = array_unique($temp); 
 //再将拆开的数组重新组装
 foreach ($temp as $k => $v)
 {
 if($stkeep) $k = $stArr[$k];
 if($ndformat)
 {
 $tempArr = explode(",",$v); 
 foreach($tempArr as $ndkey => $ndval) $output[$k][$ndArr[$ndkey]] = $ndval;
 }
 else $output[$k] = explode(",",$v); 
 }
 return $output;
}

$array2D = array('first'=>array('title'=>'1111','date'=>'2222'),'second'=>array('title'=>'1111','date'=>'2222'),'third'=>array('title'=>'2222','date'=>'3333')); 
print_r($array2D); 
print_r(unique_arr($array2D,true));