php - 配列の特定のインデックスの一意の値を取得するにはどうすればよいですか?

Question

ここに私のサンプル配列があります

    Array
(
    [0] => Array
        (
            [size] => 7.5 D(M) US
            [price] => $49.99
            [color] => Black Grey
        )

    [1] => Array
        (
            [size] => 8 D(M) US
            [price] => $46.90
            [color] => Black
        )

    [2] => Array
        (
            [size] => 8 4E US
            [price] => $49.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [3] => Array
        (
            [size] => 8.5 D(M) US
            [price] => $46.90
            [color] => Black Grey
        )

    [4] => Array
        (
            [size] => 8.5 4E US
            [price] => $49.99
            [color] => BLACK/MTLC DARK GREY/BLACK
        )

    [5] => Array
        (
            [size] => 9 D(M) US
            [price] => $49.99
            [color] => Black
        )

    [6] => Array
        (
            [size] => 9 4E US
            [price] => $49.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [7] => Array
        (
            [size] => 9.5 D(M) US
            [price] => $49.99
            [color] => Black Grey
        )

    [8] => Array
        (
            [size] => 9.5 4E US
            [price] => $49.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [9] => Array
        (
            [size] => 10 D(M) US
            [price] => $49.99
            [color] => Black
        )

    [10] => Array
        (
            [size] => 10 4E US
            [price] => $49.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [11] => Array
        (
            [size] => 10.5 D(M) US
            [price] => $49.99
            [color] => Black Grey
        )

    [12] => Array
        (
            [size] => 10.5 4E US
            [price] => $49.99
            [color] => BLACK/MTLC DARK GREY/BLACK
        )

    [13] => Array
        (
            [size] => 11 D(M) US
            [price] => $54.90
            [color] => Black
        )

    [14] => Array
        (
            [size] => 11 D(M) US
            [price] => $57.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [15] => Array
        (
            [size] => 11 4E US
            [price] => $49.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [16] => Array
        (
            [size] => 11.5 D(M) US
            [price] => $47.84
            [color] => Black Grey
        )

    [17] => Array
        (
            [size] => 12 D(M) US
            [price] => $50.90
            [color] => Black
        )

    [18] => Array
        (
            [size] => 12 4E US
            [price] => $75.00
            [color] => Black/Metallic Dark Grey/Black
        )

    [19] => Array
        (
            [size] => 13 D(M) US
            [price] => $58.59
            [color] => Black
        )

    [20] => Array
        (
            [size] => 13 4E US
            [price] => $49.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [21] => Array
        (
            [size] => 14 D(M) US
            [price] => $54.99
            [color] => Black
        )

    [22] => Array
        (
            [size] => 14 4E US
            [price] => $49.99
            [color] => Black/Metallic Dark Grey/Black
        )

    [23] => Array
        (
            [size] => 15 D(M) US
            [price] => $54.99
            [color] => Black
        )

)

そして、私が実現したいのは、"color"

echo '<select>';
    foreach($store as $item){
        echo '<option>'.$item['color'].'</option>';
    }
    echo '</select>';

そして、ここで私はそれを表示したい..

Answer 1

<?php
$items = Array
(
    Array
    (
        'size' => '7.5 D(M) US',
        'price' => '$49.99',
        'color' => 'Black Grey',
    ),
    Array
    (
        'size' => '8 D(M) US',
        'price' => '$46.90',
        'color' => 'Black'
    )
);


$colors = array();
foreach ($items as $item) {
    $colors[] = $item['color'];
}
$colors = array_unique($colors);
var_dump($colors);

Answer 2

私はそれが最高ではないことを知っていますが、これを使用できます。このようにすることで、複数のループを回避できます。

echo '<select>';
$arr = array()
foreach($store as $item){ 
    if(!in_array($item['color'],$arr)){
       echo '<option>'.$item['color'].'</option>';
    }
    array_push($arr, $item['color']);
}
echo '</select>';

Answer 3

これを試して

$unique_colors = array_reduce(
  $your_arr, 
  function($res, $elem) { 
    if (!in_array($elem['color'], $res)) {
      $res[] = $elem['color'];
    }
    return $res; 
  }, 
  array()
);

Answer 4

この小さなソリューションを使用してみてください：

$Row = Array
(
    [0] => Array
        (
            [size] => 7.5 D(M) US
            [price] => $49.99
            [color] => Black Grey
        )

    [1] => Array
        (
            [size] => 8 D(M) US
            [price] => $46.90
            [color] => Black
        )
);
$color = array();
foreach ($Row as $key => $value) {
    $Color = $value['color'];
    if(!in_array($Color, $color)) $color[] = $Color;
}

Answer 5

簡単な例を作りました

$color=array();
$color2=array();
 foreach($store as $item){
        array_push($color,$item['color']);
    }

    $color2=array_unique($color);
    echo '<select>';
    foreach($color2 as $col){
        echo '<option>'.$col.'</option>';
    }
    echo '</select>';

?>