Get from associative array only that elements which keys are specified

Hello !

It's late and I know it is a very simple question but right now I do not have an idea and deadline is near..

I've got two arrays:

$array1 = array(
  'a' => 'asdasd',
  'b' => 'gtrgrtg',
  'c' => 'fwefwefw',
  'd' => 'trhrtgr',
);
$array2 = array(
  'b', 'c'
);

What was the name of function to get a part of assoc array by keys from the second array ?

$result = array(
  'b' => 'gtrgrtg',
  'c' => 'fwefwefw',
);

Thanks !

From stackoverflow

• Try this:

  array_intersect_key($array1, array_flip($array2)).
  

  hsz : That was that ! Thanks. Shame to me. ;)

  artlung : Wow! Somehow I've missed this function before today. Cool! http://php.net/array_intersect_key

• I think there's no such function, so I will implement one:

  function array_filter_keys($array, $keys) {
    $newarray = array();
    foreach ($keys as $key) {
      if (array_key_exists($key, $array)) $newarray[$key] = $array[$key];
    }
    return $newarray;
  }
  

• I'm curious to see if there's a built in that does this. Here's how I would do it.

  $result = array();
  foreach ($array2 as $key) {
    if (array_key_exists($key, $array1) {
      $result[$key] = $array1[$key];
    }
  }