Recursive search and remove in array?

Question

I am working with a multidimensional array I want to be able to remove an array (and all children) which match an id.

The function I have tried is:

function removeKey($key, $array, $childKey = 'children'){
    if(isset($array[$key])){
        unset($array[$key]);
        return $array;
    }

    foreach($array as &$item)
        if(isset($item[$childKey]))
            $item = removeKey($key, $item[$childKey], $childKey);

    return $array;
}

My example array is:

Array
(
    [5] => Array
        (
            [id] => 5
            [parent_id] => 
            [menu_title] => Drinks
            [page_title] => Drinks
            [status] => 1
            [products] => 0
        )

    [1] => Array
        (
            [id] => 1
            [parent_id] => 
            [menu_title] => Electronics
            [page_title] => Electronics
            [status] => 1
            [products] => 0
            [children] => Array
                (
                    [2] => Array
                        (
                            [id] => 2
                            [parent_id] => 1
                            [menu_title] => Computers
                            [page_title] => Computers
                            [status] => 1
                            [products] => 0
                            [children] => Array
                                (
                                    [4] => Array
                                        (
                                            [id] => 4
                                            [parent_id] => 2
                                            [menu_title] => Apple
                                            [page_title] => Apple - Imacs and Macbooks
                                            [status] => 1
                                            [products] => 0
                                        )

                                )

                        )

                    [3] => Array
                        (
                            [id] => 3
                            [parent_id] => 1
                            [menu_title] => Mobile Phones
                            [page_title] => Mobile Phones
                            [status] => 1
                            [products] => 0
                        )

                )

        )

)

and the result I am looking for (calling the function with (2, $array, 'children')) is:

Array
(
    [5] => Array
        (
            [id] => 5
            [parent_id] => 
            [menu_title] => Drinks
            [page_title] => Drinks
            [status] => 1
            [products] => 0
        )

    [1] => Array
        (
            [id] => 1
            [parent_id] => 
            [menu_title] => Electronics
            [page_title] => Electronics
            [status] => 1
            [products] => 0
            [children] => Array
                (

                    [3] => Array
                        (
                            [id] => 3
                            [parent_id] => 1
                            [menu_title] => Mobile Phones
                            [page_title] => Mobile Phones
                            [status] => 1
                            [products] => 0
                        )

                )

        )

)

but the result I am getting is

Array
(
    [5] => Array
        (
            [id] => 5
            [parent_id] => 
            [menu_title] => Drinks
            [page_title] => Drinks
            [status] => 1
            [products] => 0
        )

    [1] => Array
        (
            [3] => Array
                (
                    [id] => 3
                    [parent_id] => 1
                    [menu_title] => Mobile Phones
                    [page_title] => Mobile Phones
                    [status] => 1
                    [products] => 0
                )

        )

)

I have no idea what's going on here!

score 2 · Accepted Answer · answered Aug 21 '12 at 11:06

2

You can ease things by only using references.

function removeKey($key, &$array, $childKey = 'children'){
    if(isset($array[$key])){
        unset($array[$key]);
        return;
    }

    foreach($array as &$item)
        if(isset($item[$childKey]))
            removeKey($key, $item[$childKey], $childKey);
}

Example:

$arr = array(...);
removeKey('key', $arr, $chilKey);
// Just continue using $arr

answered Aug 21 '12 at 11:06

Daniel M

3,369
20
30

Cheers, that works, but What was I actually doing wrong to have the above output? – Hailwood Aug 21 '12 at 11:08
Didn't check that to be honest, but you're replacing the $item node (which is the one containing the 'children' node) by the cleaned array. However, using references should be much easier. – Daniel M Aug 21 '12 at 11:11

score 0 · Answer 2 · answered Aug 19 '17 at 21:07

What about multidimensional array? I was researched for a couple of hours for this solution, nowhere found an optimal solution. so, i wrote it by myself

function allow_keys($arr, $keys)
    {
        $saved = [];

        foreach ($keys as $key => $value) {
            if (is_int($key) || is_int($value)) {
                $keysKey = $value;
            } else {
                $keysKey = $key;
            }
            if (isset($arr[$keysKey])) {

                $saved[$keysKey] = $arr[$keysKey];
                if (is_array($value)) {

                    $saved[$keysKey] = allow_keys($saved[$keysKey], $keys[$keysKey]);
                }
            }
        }
        return $saved;
    }

use: example

$array = [
        'key1' => 'kw',
        'loaa'=> ['looo'],
        'k'    => [
            'prope' => [
                'prop'  => ['proo', 'prot', 'loolooo', 'de'],
                'prop2' => ['hun' => 'lu'],
            ],
            'prop1' => [

            ],
        ],
    ];

call: example

allow_keys($array, ['key1', 'k' => ['prope' => ['prop' => [0, 1], 'prop2']]])

output:

Array ( [key1] => kw [k] => Array ( [prope] => Array ( [prop] => Array ( [0] => proo [1] => prot ) [prop2] => Array ( [hun] => lu ) ) ) )

so you get only needed keys from the multidimensional array. it is not limited only for "multidimensional", you can use it by passing an array like

['key1', 'loaa']

output you get:

Array ( [key1] => kw [loaa] => Array ( [0] => looo ) )

hope someone helps this one, as i searched a lot, and nothing found. cheers!

maybe it is not the direct answer for this question, but when you're making an research on the google by question "Recursive search and remove in array" you find these topics,which do not answer for this question in the right way. — Georgy Sharapov, Aug 19 '17 at 21:23
Please don't repost your answer. You should edit your answer to fit the question. — Papershine, Aug 20 '17 at 05:32

Recursive search and remove in array?

2 Answers2

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