値関数による PHP 配列のグループ化とベストプラクティス

array_group_by(array $array, mixed $key_or_callback, bool $preserve_keys = false): array

$fruits = [ ['name' => 'Apple', 'type' => 'Red'], ['name' => 'Banana', 'type' => 'Yellow'], ['name' => 'Orange', 'type' => 'Orange'], ['name' => 'Mango', 'type' => 'Yellow'], ]; $grouped_by_type = array_group_by($fruits, 'type'); // 输出按类型分组后的数组 print_r($grouped_by_type);

Array ( [Red] => Array ( [0] => Array ( [name] => Apple [type] => Red ) ) [Yellow] => Array ( [0] => Array ( [name] => Banana [type] => Yellow ) [1] => Array ( [name] => Mango [type] => Yellow ) ) [Orange] => Array ( [0] => Array ( [name] => Orange [type] => Orange ) ) )

function group_by(array $array, string $key): array { $result = []; foreach ($array as $item) { $result[$item[$key]][] = $item; } return $result; }

$grouped_by_type_and_name = array_reduce($fruits, function($result, $item) { $result[$item['type']][$item['name']] = $item; return $result; }, []);

$grouped_by_name = array_column($fruits, null, 'name');