序列化和惟一的替代方案

$test = [ ['abc','def'], ['ghi','jkl'], ['mno','pql'], ['abc','def'], ['ghi','jkl'], ['mno','pql'], ]; $result = array_reduce( $test, function($carry,$item){ if(!in_array($item,$carry)) { array_push($carry,$item); } return $carry; }, [] ); var_dump($result); /* php unique.php array(3) { [0] => array(2) { [0] => string(3) "abc" [1] => string(3) "def" } [1] => array(2) { [0] => string(3) "ghi" [1] => string(3) "jkl" } [2] => array(2) { [0] => string(3) "mno" [1] => string(3) "pql" } } */

如果您需要消除特定键上的重复项，例如mysqli id，这里有一个简单的函数

function search_array_compact($data,$key){
    $compact = [];
    foreach($data as $row){
        if(!in_array($row[$key],$compact)){
            $compact[] = $row;
        }
    }
    return $compact;
}

加分 您可以传递一个键数组并添加一个外部foreach，但每增加一个键将慢2倍。

另一种方式。也会保存密钥。

function array_unique_multidimensional($input)
{
    $serialized = array_map('serialize', $input);
    $unique = array_unique($serialized);
    return array_intersect_key($input, $unique);
}

唯一一个多维数组的简单而合理的方法如下:

如果你有一个这样的数组:

Array
(
    [Key1] => Array
        (
            [0] => Value1
            [1] => Value2
            [2] => Value1
            [3] => Value3
            [4] => Value1
        )
    [Key2] => Array
        (
            [0] => Value1
            [1] => Value2
            [2] => Value1
            [3] => Value3
            [4] => Value4
        )
)

使用foreach来解决这个问题:

foreach($array as $k=>$v){
    $unique=array_unique($v);
    $array[$k]=$unique;
}

它会给你以下结果:

Array
(
    [Key1] => Array
        (
            [0] => Value1
            [1] => Value2
            [3] => Value3
        )
    [Key2] => Array
        (
            [0] => Value1
            [1] => Value2
            [3] => Value3
            [4] => Value4
        )
)

如果你想重新排列键的顺序，

foreach($array as $k=>$v){
    $unique= array_values(array_unique($v));
    $array[$k]=$unique;
}

这个操作会给你这样排列的键值:

Array
(
    [Key1] => Array
        (
            [0] => Value1
            [1] => Value2
            [2] => Value3
        )
    [Key2] => Array
        (
            [0] => Value1
            [1] => Value2
            [2] => Value3
            [3] => Value4
        )
)

我希望这能澄清一切。

如果"remove duplicate "的意思是"remove duplicate，但保留一个"，一个解决方案可能是首先在"identifier column"上应用array_unique(…)，然后在原始数组中删除所有已从列数组中删除的键:

$array = [
    [
        'id' => '123',
        'foo' => 'aaa',
        'bar' => 'bbb'
    ],
    [
        'id' => '123',
        'foo' => 'ccc',
        'bar' => 'ddd'
    ],
    [
        'id' => '567',
        'foo' => 'eee',
        'bar' => 'fff'
    ]
];

$ids = array_column($array, 'id');
$ids = array_unique($ids);
$array = array_filter($array, function ($key, $value) use ($ids) {
    return in_array($value, array_keys($ids));
}, ARRAY_FILTER_USE_BOTH);

结果是:

Array
(
    [0] => Array
        (
            [id] => 123
            [foo] => aaa
            [bar] => bbb
        )

    [2] => Array
        (
            [id] => 567
            [foo] => eee
            [bar] => fff
        )

)

对此，array_unique()文档上的用户注释提供了许多解决方案。这是其中之一:

kenrbnsn at rbnsn dot com 27-Sep-2005 12:09 Yet another Array_Unique for multi-demensioned arrays. I've only tested this on two-demensioned arrays, but it could probably be generalized for more, or made to use recursion. This function uses the serialize, array_unique, and unserialize functions to do the work. 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); }

这来自http://ca3.php.net/manual/en/function.array-unique.php#57202。