All keys exist in array.

PHP-All Keys Exist in Array.

//The values in this arrays contains the names of the indexes (keys) that should exist in the data array
$required = array('key1', 'key2', 'key3' );

$data = array(
    'key1' => 10,
    'key2' => 20,
    'key3' => 30,
    'key4' => 40
);

if(count(array_intersect_key(array_flip($required), $data)) === count($required)) {
    //All required keys exist!              
}

?>