Filter an array based on a white list of keys

array-keys-white-list.php

<?php

/**
 * Filter an array based on a white list of keys
 *
 * @param array $array
 * @param array $keys
 * @return array
 */
function array_keys_white_list( array $array, array $keys ) {
	foreach ( $array as $key => $value ) {
		if ( ! in_array( $key, $keys ) ) {
			unset( $array[$key] );
		}
	}
	return $array;
}