Code Error

//when I use......


$found_user=User::find_user_by_id(2);
echo $found_user['id'];

//with

public static function find_user_by_id ($id){
$result_set= self::find_this_query("SELECT * FROM users WHERE id=$id");

$found_user=mysqli_fetch_array($result_set);
return $found_user;

        }

//I get a result id returned

//but when I use

$found_user=User::find_user_by_id(2);

$myUser=User::instantiate($found_user);

echo $myUser->id;


//with

public static function instantiate($found_user){

$the_object=new self;

foreach ($found_user as $the_attribute => $value) {
if($the_object->has_the_attribute($the_attribute)){
$the_object->the_attribute=$value;

        }

//I get a blank browser