I have an array like that:

[
        [
            "id"     => 1,
            "name"   => "Root Category",
            "child"  => [
                "id"    => 2,
                "name"  => "Sub category",
                "child" => [
                    "id"   => 3,
                    "name" => "Last level category",
                ],
            ],
        ],
        [
            "id"     => 1,
            "name"   => "Root Category",
            "child"  => [
                "id"    => 2,
                "name"  => "Sub category",
                "child" => [
                    "id"   => 6,
                    "name" => "Last level category #2",
                ],
            ],
        ],
    ];

In these arrays first level and second level are the same, only the last level is different. I want to combine them into one array. I want to receive result like that:

[
        [
            "id"     => 1,
            "name"   => "Root Category",
            "child"  => [
                "id"    => 2,
                "name"  => "Sub category",
                "child" => [
                    [
                        "id"   => 3,
                        "name" => "Last level category",
                    ],
                    [
                        "id"   => 6,
                        "name" => "Last level category #2",
                    ]
                ],
            ],
        ]
    ];

CodePudding user response：

collect($arr)
        ->groupBy(function ($item) {
            return $item['id'] . $item['child']['id'];
        })
        ->map(function ($group) {
            $first = $group->first();

            $first['child']['child'] = $group->pluck('child.child')->toArray();

            return $first;
        })
        ->values()
        ->toArray()

CodePudding user response：

Solution using raw PHP:

$categories = [
  [
    "id"     => 1,
    "name"   => "Root Category",
    "child"  => [
      "id"    => 2,
      "name"  => "Sub category",
      "child" => [
        "id"   => 3,
        "name" => "Last level category",
      ],
    ],
  ],
  [
    "id"     => 1,
    "name"   => "Root Category",
    "child"  => [
      "id"    => 2,
      "name"  => "Sub category",
      "child" => [
        "id"   => 6,
        "name" => "Last level category #2",
      ],
    ],
  ],
];

$children = [];

foreach ($categories as $category) {
  $children[] = $category['child']['child'];
}

$categories = $categories[0];
$categories['child']['child'] = $children;

echo "<pre>";
print_r($categories);
die();

// Result

Array
(
    [id] => 1
    [name] => Root Category
    [child] => Array
        (
            [id] => 2
            [name] => Sub category
            [child] => Array
                (
                    [0] => Array
                        (
                            [id] => 3
                            [name] => Last level category
                        )

                    [1] => Array
                        (
                            [id] => 6
                            [name] => Last level category #2
                        )

                )

        )

)