PHP Extract Function

extract.php

<?php

function array_extract(array $input, array $keys){
  $output = []; 
  foreach ($keys as $key){
    if (!array_key_exists($key, $input)) continue;
    $output[$key] = $input[$key];
  }
  return $output;
}


$super = [ 
  'one'   => 1,
  'two'   => 2,
  'three' => 3
];

$sub = array_extract($super, ['one', 'three']);

var_export($sub);