Remove unwanted elements from subarrays in multidimensional array

Question

I have a multidimensional array like this:

[
    [
        'id' => 1,
        'name' => 'John',
        'address' => 'Some address 1'
        'city' => 'NY'
    ],
    [
        'id' => 2,
        'name' => 'Jack',
        'address' => 'Some address 2'
        'city' => 'NY'
    ]
    ...
  
    [ ... ]
]

How can I remove elements in all subarrays and only retain the id and name keys with their values?

Answer 1

Would this work?

$result = array_map(function($arr) {
    return [
        'id' => $arr['id'],
        'name' => $arr['name']
    ];
}, $orig_array);

Answer 2

You want to retain the first two associative elements, so you can make array_slice() calls within array_map(). (Demo)

var_export(
    array_map(fn($row) => array_slice($row, 0, 2), $array)
);

---

Or mapped called of array_intersect_key() against an establish whitelist array. (Demo)

$keep = ['id' => '', 'name' => ''];
var_export(
    array_map(
        fn($row) => array_intersect_key($row, $keep),
        $array
    )
)

---

Or, you could use array destructuring inside of a classic foreach() and make iterated compact() calls. (Demo)

$result = [];
foreach ($array as ['id' => $id, 'name' => $name]) {
    $result[] = compact(['id', 'name']);
}
var_export($result);

Answer 3

If you want to edit the same array in place, you can simply iterate over them and unset them.

<?php 

$preserve_keys = ['id','name'];

foreach($arr as &$data){
    foreach($data as $key => $value){
        if(!in_array($key,$preserve_keys)){
            unset($data[$key]);
        }
    }
}

---

If you want it as a separate result, loop over and add it to the new array.

<?php

$new_result = [];

foreach($arr as $data){
    $new_result[] = [
        'id' => $data['id'],
        'name' => $data['name']
    ];
}

print_r($new_result);