php - php 二層配列キー検索

Question

$arr = array (

    0 => array(
        'id' => 1,
        'name' => 'john'
    ),
    1 => array(
        'id' => 4,
        'name' => 'elisabeth'
    )
);

私たちが知っているのは内部配列の 'id' だけだとしましょう。私たちの id を含む配列を含む $arr 要素を検索する最良の方法は何でしょうか?

Answer 1

function search($id)
{
    foreach ($arr as $item) {
        if (isset($item['id']) && $item['id'] == $id) {
            return $item; // or whatever you want to return
        }
    }
}

アップデート：

function search($id)
{
    foreach ($arr as $key => $item) {
        if (isset($item['id']) && $item['id'] == $id) {
            return $key; // Return key...
        }
    }
}

Answer 2

array_filterを使用する

$arr = array (

    0 => array(
        'id' => 1,
        'name' => 'john'
    ),
    1 => array(
        'id' => 4,
        'name' => 'elisabeth'
    )
);

$id = 1;
$result = array_filter($arr, function($el) use ($id) {
    return $el['id'] == $id;
});
echo '<pre>', var_dump($result), '</pre>';

Answer 3

$array = array(
    0 => array(
        'id' => 1,
        'name' => 'john'
    ),
    1 => array(
        'id' => 4,
        'name' => 'elisabeth'
    )
);

$search = 4;
$result = null;

array_walk(
    $array,
    function ($element) use ($search, &$result) {
        if (isset($element['id']) && (int)$element['id'] === (int)$search) {
            $result = $element;
        }
    }
);

var_dump($result);

Answer 4

$arr = array (

0 => array(
    'id' => 1,
    'name' => 'john'
),
1 => array(
    'id' => 4,
    'name' => 'elisabeth'
)
);
foreach($arr as $a)
if($a["id"] == 4)
echo $a["name"];