如果數組有重復項，則鍵為空值

Question

我有這個數組

    Array
(
    [0] => Array
        (
            [user_id] => 78
            [post_id] => 3
            [post_user_added_id] => 2
        )

    [1] => Array
        (
            [user_id] => 76
            [post_id] => 3
            [post_user_added_id] => 16
        )

    [2] => Array
        (
            [user_id] => 78
            [post_id] => 3
            [post_user_added_id] => 12
        )

    [3] => Array
        (
            [user_id] => 76
            [post_id] => 9
            [post_user_added_id] => 15
        )

     [4] => Array
         (
             [user_id] => 77
             [post_id] => 9
             [post_user_added_id] => 15
         )

我想要做的是，如果 key post_id重復，我只想清空它並保留一個，這樣我的最終數組將如下所示

 Array
(
    [0] => Array
        (
            [user_id] => 78
            [post_id] => 3
            [post_user_added_id] => 2
        )

    [1] => Array
        (
            [user_id] => 76
            [post_id] => 
            [post_user_added_id] => 16
        )

    [2] => Array
        (
            [user_id] => 78
            [post_id] => 
            [post_user_added_id] => 12
        )

    [3] => Array
        (
            [user_id] => 76
            [post_id] => 9
            [post_user_added_id] => 15
        )

     [4] => Array
         (
             [user_id] => 77
             [post_id] => 
             [post_user_added_id] => 15
         )

我試過這段代碼，但它似乎不起作用它刪除了整個數組

                           foreach($arry as $k => $v)
                            {
                                foreach($arry as $key => $value)
                                {
                                    if($k != $key && $v['post_id'] == $value['post_id'])
                                    {
                                        unset($arry [$k]);
                                    }
                                }
                            }
                            print_r($arry);

Answer 1

您可以使用ternary運算符執行foreach

$last = null;//this will keep the previous post_id
foreach($arr as &$v){
 ($last && $last == $v['post_id']) ? ($v['post_id'] = '') : ($last = $v['post_id']);
}
print_r($arr);

工作示例：- https://3v4l.org/RiU9J

Answer 2

也許如果您使用堆棧進行比較？ 編輯：重寫代碼...

$stack=[];
foreach ($array as $index => $subarray){
    if(in_array($subarray['post_id'], $stack)) {
        $array[$index]['post_id'] = null;

    }
    else $stack[]=$subarray['post_id'];
}
print_r($array);

示例： https : //3v4l.org/FsPUG
希望這可以幫助！

Answer 3

在這里試試這個。

$tempArr = [];
$resArr = [];
foreach($orignalArr as $key=>$obj){
    if(in_array($obj['post_id'], $tempArr)){
        $obj['post_id'] = '';
        $resArr[] = $obj;
    }else{
        $tempArr[] = $obj['post_id'];
        $resArr[] = $obj;
    }
}

print_r($resArr);

Answer 4

使用您的數組值代替 $arr 並嘗試像以下代碼一樣過濾數組：

 $arr = array(
        array(
            'user_id'=>15,
            'post_id'=>3,
            'post_user_added_id'=>2
            ),

            array(
            'user_id'=>16,
            'post_id'=>3,
            'post_user_added_id'=>2
            ),

         array(
            'user_id'=>18,
            'post_id'=>3,
            'post_user_added_id'=>2
            ),

             array(
            'user_id'=>18,
            'post_id'=>3,
            'post_user_added_id'=>2
            ),

             array(
            'user_id'=>16,
            'post_id'=>3,
            'post_user_added_id'=>2
            ),
    );

    $postids = array();
    foreach($arr as $key=>$val){

        if(in_array($val['post_id'], $postids)){ 
            $arr[$key]['post_id'] = '';
        }else{
            $postids[] = $val['post_id'];
        }
    }

    echo "<pre>";print_r($arr);exit;    

輸出 ：

Array
(
    [0] => Array
        (
            [user_id] => 15
            [post_id] => 3
            [post_user_added_id] => 2
        )

    [1] => Array
        (
            [user_id] => 16
            [post_id] => 
            [post_user_added_id] => 2
        )

    [2] => Array
        (
            [user_id] => 18
            [post_id] => 
            [post_user_added_id] => 2
        )

    [3] => Array
        (
            [user_id] => 18
            [post_id] => 
            [post_user_added_id] => 2
        )

    [4] => Array
        (
            [user_id] => 16
            [post_id] => 
            [post_user_added_id] => 2
        )

)

Answer 5

嘗試這個 ：

// example code
$arrayResult = array();
$arry = [
    1 =>
        [
            'user_id' => 78,
            'post_id' => 3,
            'post_user_added_id' => 2
        ],

    2=>
        [
            'user_id' => 76,
            'post_id' => 3,
            'post_user_added_id' => 16
        ],
    3 =>
        [
            'user_id' => 78,
        'post_id' => 3,
            'post_user_added_id' => 12
        ],

    4 =>
        [
            'user_id' => 76,
            'post_id' => 9,
            'post_user_added_id' => 15
        ],

     5 =>
         [
            'user_id' => 77,
            'post_id' => 9,
            'post_user_added_id' => 15
         ]];

$final = array();
foreach($arry as $a)
{
    if (in_array($a['post_id'], $arrayResult)) {
        $a['post_id'] = 0;
    }else{
        $arrayResult[] = $a['post_id'];
    }
    $final[] = $a;
}

var_dump($final);