PHP - create new array with only selected keys from an existing array

Question

What is the simplest way to get only selected keys and its values from an array in PHP? For example, if I have an array:

$meta = [
      "nickname" => [
        0 => "John"
      ]
      "first_name" =>  [
        0 => "John"
      ]
      "last_name" => [
        0 => "Doe"
      ]
      "description" => array:1 [
        0 => ""
      ]
      "rich_editing" => [
        0 => "true"
      ]
      "comment_shortcuts" => [
        0 => "false"
      ]
      "admin_color" => [
        0 => "fresh"
      ]
      "use_ssl" => array:1 [
        0 => "0"
      ]
      "show_admin_bar_front" => [
        0 => "true"
      ]
      "locale" => [
        0 => ""
      ]
      "wp_capabilities" => [
        0 => "a:1:{s:10:"subscriber";b:1;}"
      ]
      "wp_user_level" => [
        0 => "0"
      ]
      "dismissed_wp_pointers" => [
        0 => ""
      ]
      "department" => [
        0 => "Administrasjon"
      ]
      "region" => [
        0 => "Oslo"
      ]
      "industry" => [
        0 => "Bane"
      ]
    ]

What is the simplest way to get a new array with only selected keys like for example nickname, first_name, last_name, etc?

Answer 1

Using array_flip() and array_intersect_key():

$cleanArray = array_intersect_key(
    $fullArray,  // the array with all keys
    array_flip(['nickname', 'first_name', 'last_name']) // keys to be extracted
);

Answer 2

Try this;

$newArray = array();
$newArray['nickname'] = $meta['nickname'];
$newArray['first_name'] = $meta['first_name'];
$newArray['last_name'] = $meta['last_name'];

This is useful if number of keys are not many.

And if keys are many; then you can go for

$requiredKeys = ['nickname','first_name','last_name'];
foreach ($arr as $key => $value) {

        if(in_array($key,$requiredKeys))
                $newArray[$key] = $meta[$key];
}