multidimensional array remove item from child array-CodePudding

i have a problem with my multidimensional array. I want to remove some items from child array by $id value.

here is my multidimensional example array and selectedIds:

$myArray = [
    ['id' => '2', 
    'name' => 'Punk'
    ],[
    'id' => '5', 
    'name' => 'Rock', 
    'children' => [
        '30' => ['id' => '30', 
                'name' => 'Hard Rock', 
                'parentId' => '5'
                ], 
        '40' => ['id' => '40', 
                'name' => 'Soft Rock', 
                'parentId' => '5'
                ],  
        '50' => ['id' => '50', 
                'name' => 'Glam Rock', 
                'parentId' => '5'
                ]
        ]
    ]
];

$selectedIds = [2,5,30];

and i want to remove from array those items which are not in selectedIds array.

so i want to have output:

$outputArray = [
    [
    'id' => '2', 
    'name' => 'Punk'
    ],[
    'id' => '5', 
    'name' => 'Rock', 
    'children' => [
            '30' => ['id' => '30', 
                    'name' => 'Hard Rock', 
                    'parentId' => '5']
                ]
    ]
];

i try to make it with foreach and array_key_exist but its not correct:

foreach ($myArray as $key=>$value) {
    if (array_key_exists('children', $value)) {
        foreach ($selectedIds as $id) {
            if (isset($value['children'][$id])) {
                $outputArray[] = $value['children'][$id];
            }
        }
    }
}
print_r($outputArray);

this outpus is only item with id 30

CodePudding user response：

write else part into your code if array has no children key

else{
    foreach ($selectedIds as $id) {
        if ($value['id'] == $id) {
            $outputArray[$key] = $value;
        }
    }
}

Final code

<?PHP
$myArray = [
    [
        'id' => '2', 
        'name' => 'Punk'
    ],
    [
        'id' => '5', 
        'name' => 'Rock', 
        'children' => [
            '30' => ['id' => '30', 
                    'name' => 'Hard Rock', 
                    'parentId' => '5'
                    ], 
            '40' => ['id' => '40', 
                    'name' => 'Soft Rock', 
                    'parentId' => '5'
                    ],  
            '50' => ['id' => '50', 
                    'name' => 'Glam Rock', 
                    'parentId' => '5'
                    ]
            ]
        ]
];

$selectedIds = [2,5,30];

foreach ($myArray as $key=>$value) {
    if (array_key_exists('children', $value)) {
        foreach ($selectedIds as $id) {
            if (isset($value['children'][$id])) {
                $outputArray[$key]['id'] = $value['id'];
                $outputArray[$key]['name'] = $value['name'];
                $outputArray[$key]['children'][$id] = $value['children'][$id];
            }
        }
    }else{
        foreach ($selectedIds as $id) {
            if ($value['id'] == $id) {
                $outputArray[$key] = $value;
            }
        }
    }
}
echo "<pre>";
print_r($outputArray);
?>

Output

Array
(
    [0] => Array
        (
            [id] => 2
            [name] => Punk
        )

    [1] => Array
        (
            [id] => 5
            [name] => Rock
            [children] => Array
                (
                    [30] => Array
                        (
                            [id] => 30
                            [name] => Hard Rock
                            [parentId] => 5
                        )

                )

        )

)

CodePudding user response：

Hey i make other code more simple. That´s here:

just change a bit the foreach content:

foreach ($myArray as $key=>&$value) {
    if (array_key_exists('children', $value)) {
        $value['children'] = array_intersect_key($value['children'], array_flip($selectedIds));
    }
}

Use array_flipfor transform keys on values and array_intersect_keyfor get only they id´s that exist in 2 arrays.

here you can see a live demo

NOTE: take care that i´m passing the value by referer &$value in the foreach for modify the original array, if you dont want this just duplicate the original array and modify the second.