PHP 二维数组中某些key合并相同部分，不同部分组成新的数组

Question

如何将 $arr 数组变成 $newArr 的结构 $arr = [ [ 'id' => '1', 'name' => 'a', 'attr' => '红色', 'val' => '10' ], [ 'id' => '1', 'name' => 'a', 'attr' => '蓝色', 'val' => '11' ], [ 'id' => '2', 'name' => 'b', 'attr' => '绿色', 'val' => '12' ], [ 'id' => '2', 'name' => 'b', 'attr' => '黄色', 'val' => '13' ], ]; 要变成的数组结构： $arr = [ [ 'id' => '1', 'name' => 'a', 'info' => [ ['attr' => '红色', 'val' => '10'] ['attr' => '蓝色', 'val' => '11'] ] ], [ 'id' => '2', 'name' => 'b', 'info' => [ ['attr' => '绿色', 'val' => '12'] ['attr' => '绿色', 'val' => '13'] ] ] ];

Answer 1

$data = [];
array_map(function($key) use (&$data){
    if (!isset($data[$key['id']])) {
        $data[$key['id']] = [
            'id' => $key['id'],
            'name' => $key['name'],
        ];
    }
    $data[$key['id']]['info'][] = [
        'attr' => $key['attr'],
        'val' => $key['val'],
    ];
}, $arr);
print_r(array_values($data));