以二维数组为例，来说明针对任意键值的去重，时间复杂度为~O(n)，只用一个foreach循环：
<?php $arr = array(
'0'=>array(
'name'=>'james',
'age'=>30,
),
'1'=>array(
'name'=>'susu',
'age'=>26,
),
'2'=>array(
'name'=>'james',
'age'=>30,
),
'new'=>array(
'name'=>'kube',
'age'=>37,
),
'list'=>array(
'name'=>'kube',
'age'=>27,
),
);
/*针对任意键值来进行去重*/
function getArrayUniqueByKeys($arr)
{
$arr_out =array();
foreach($arr as $k => $v)
{
$key_out = $v['name']."-".$v['age']; //提取内部一维数组的key(name age)作为外部数组的键
if(array_key_exists($key_out,$arr_out)){
continue;
}
else{
$arr_out[$key_out] = $arr[$k]; //以key_out作为外部数组的键
$arr_wish[$k] = $arr[$k]; //实现二维数组唯一性
}
}
return $arr_wish;
}
$arr_wish = getArrayUniqueByKeys($arr);
printf("As for the arbitrarily key:<br>");
print_r($arr_wish);
echo "<br>";
?>输出结果：
As for the arbitrarily key:
Array ( [0] => Array ( [name] => james [age] => 30 ) [1] => Array ( [name] => susu [age] => 26 ) [new] => Array ( [name] => kube [age] => 37 ) [list] => Array ( [name] => kube [age] => 27 ) )
开发实例：优惠券去重（以优惠金额-订单金额字段不能重复去除重复项）
要求：优惠金额和订单金额都一样的优惠券要求只展示一张给用户选择，并且展示最快到期的那张：
<?php $arrCoupon = array(
'0'=>array(
'couponCode' => '3033323852301056',
'usableStartTime' => "1439740800",
'usableEndTime'=>"1440798100",
'couponAmount' =>100,
'orderAmount'=> 800,
),
'1'=>array(
'couponCode' => '3033323852301057',
'usableStartTime' => "1439740800",
'usableEndTime'=>"1440768100",
'couponAmount' =>100,
'orderAmount'=> 800,
),
'2'=>array(
'couponCode' => '3033323852301058',
'usableStartTime' => "1439740800",
'usableEndTime'=>"1440788100",
'couponAmount' =>100,
'orderAmount'=> 800,
),
'3'=>array(
'couponCode' => '3033323852301059',
'usableStartTime' => "1439740800",
'usableEndTime'=>"1440779100",
'couponAmount' =>200,
'orderAmount'=> 800,
),
'4'=>array(
'couponCode' => '3033323852301060',
'usableStartTime' => "1439740800",
'usableEndTime'=>"1440758100",
'couponAmount' =>200,
'orderAmount'=> 800,
),
'5'=>array(
'couponCode' => '3033323852301061',
'usableStartTime' => "1439740800",
'usableEndTime'=>"1440798100",
'couponAmount' =>200,
'orderAmount'=> 800,
),
);
//print_r($arrCoupon);
function getArrayUniqueByKey($arr)
{
$arrWish = array();
$today = time();
foreach ($arr as $k => $v) {
if (($v['usableStartTime'] intval($v['usableEndTime'])) {
$arrWish[$keyOut] = $v; //如果原来数组中结束时间大的话，就交换值
}
continue;
}
$arrWish[$keyOut] = $v; //实现二维数组唯一性
}
continue;
}
return $arrWish;
}
$arrWant = getArrayUniqueByKey($arrCoupon);
print_r($arrWant);
?>
输出结果：
Array( [100-800] =>Array ( [couponCode] => 3033323852301057 [usableStartTime] => 1439740800[usableEndTime] => 1440768100 [couponAmount] => 100 [orderAmount] =>800 ) [200-800]=>
Array ( [couponCode] => 3033323852301060 [usableStartTime] =>1439740800 [usableEndTime] => 1440758100 [couponAmount] => 200 [orderAmount]=> 800 ) )
以上就介绍了php多维数组的去重（针对任意的键值进行去重）--二维数组的唯一--时间复杂度~On，包括了方面的内容，希望对PHP教程有兴趣的朋友有所帮助。
