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サブ配列値で配列をグループ化する

興味深い課題があります。次の形式のサブ配列の配列があります。

array
(
    a => array ( id = 20, name = chimpanzee )
    b => array ( id = 40, name = meeting )
    c => array ( id = 20, name = dynasty )
    d => array ( id = 50, name = chocolate )
    e => array ( id = 10, name = bananas )
    f => array ( id = 50, name = fantasy )
    g => array ( id = 50, name = football )
)

そして、各サブアレイのidフィールドに基づいて、新しいアレイにグループ化したいと思います。

array
(
    10 => array
          (
            e => array ( id = 10, name = bananas )
          )
    20 => array
          (
            a => array ( id = 20, name = chimpanzee )
            c => array ( id = 20, name = dynasty )
          )
    40 => array
          (
            b => array ( id = 40, name = meeting )
          )
    50 => array
          (
            d => array ( id = 50, name = chocolate )
            f => array ( id = 50, name = fantasy )
            g => array ( id = 50, name = football )
          )
)

ありがとう！

phparraysalgorithmsorting
35
Anson Kao
$arr = array();

foreach ($old_arr as $key => $item) {
   $arr[$item['id']][$key] = $item;
}

ksort($arr, SORT_NUMERIC);
92
Tim Cooper
foreach($array as $key => $value){
   $newarray[$value['id']][$key] = $value;
}

var_dump($newarray);

ケーキ;）

8
amosrivera

次のコードは、@ Tim Cooperのコードを調整してUndefined index: id内部配列の1つにidが含まれていない場合のエラー

$arr = array();

foreach($old_arr as $key => $item)
{
    if(array_key_exists('id', $item))
        $arr[$item['id']][$key] = $item;
}

ksort($arr, SORT_NUMERIC);

ただし、IDのない内部配列は削除されます。

例えば。

$old_arr = array(
    'a' => array ( 'id' => 20, 'name' => 'chimpanzee' ),
    'b' => array ( 'id' => 40, 'name' => 'meeting' ),
    'c' => array ( 'id' => 20, 'name' => 'dynasty' ),
    'd' => array ( 'id' => 50, 'name' => 'chocolate' ),
    'e' => array ( 'id' => 10, 'name' => 'bananas' ),
    'f' => array ( 'id' => 50, 'name' => 'fantasy' ),
    'g' => array ( 'id' => 50, 'name' => 'football' ),
    'h' => array ( 'name' => 'bob' )
);

'h'配列を完全に削除します。

4
Herbert
<?php

$array = array(
    'a' => array ( 'id' => 20, 'names' => 'chimpanzee' ),
    'b' => array ( 'id' => 40, 'name' => 'meeting' ),
    'c' => array ( 'id' => 20, 'name' => 'dynasty' ),
    'd' => array ( 'id' => 50, 'name' => 'chocolate' ),
    'e' => array ( 'id' => 10, 'name' => 'bananas' ),
    'f' => array ( 'id' => 50, 'name' => 'fantasy' ),
    'g' => array ( 'id' => 50, 'name' => 'football' )
);

$result = array();

foreach($array as $key => $value){
    $id = $value['id'];
    if(!isset($result[$id])) $result[$id] = array();
    $result[$id] = array($key => $value);
}

var_dump($result);
?>

デモ： http://codepad.org/yvU95m9k

1
Ilia Choly

Arrays :: gorupBy form ouzo-goodies を使用することもできます：

$groupBy = Arrays::groupBy($array, Functions::extract()->id);

print_r($groupBy);

そして結果：

Array
(
    [20] => Array
        (
            [0] => Array
                (
                    [id] => 20
                    [name] => chimpanzee
                )

            [1] => Array
                (
                    [id] => 20
                    [name] => dynasty
                )

        )

    [40] => Array
        (
            [0] => Array
                (
                    [id] => 40
                    [name] => meeting
                )

        )

    [50] => Array
        (
            [0] => Array
                (
                    [id] => 50
                    [name] => chocolate
                )

            [1] => Array
                (
                    [id] => 50
                    [name] => fantasy
                )

            [2] => Array
                (
                    [id] => 50
                    [name] => football
                )

        )

    [10] => Array
        (
            [0] => Array
                (
                    [id] => 10
                    [name] => bananas
                )

        )

)

そして、ここに Arrays および Functions のドキュメントがあります。

1
Piotr Olaszewski