Function that uses an exception to check if user exists

Question

I have a User class that will throw an exception if the userid provided in the parameter does not correspond with a user.

I've written a helper function that will return true or false depending on whether a userid belongs to a user or not, but was wondering if my use of a try {} catch {} to do so is correct:

 private function userExists($userid)
 {
 $user_does_not_exist = false;
 try
 {
 $user = new User($userid);
 }
 catch (Exception $e)
 {
 $user_does_not_exist = true; 
 }
 return $user_does_not_exist;
 }

Any and all critique is greatly appreciated.

Answer 1

I would suggest working the other way around. Expect that a user does not exist and only return true if a user is found.

private function UserExists($userId)
{
 $userExists = false;
 try
 {
 $user = new User($userId);
 if($user !== null)
 $userExists = true;
 }
 catch (Exception $e)
 {
 //handle exception
 }
 return $userExists;
}

You can drive this further and ease things by not using a variable to return, like this:

private function UserExists($userId)
{
 try
 {
 return new User($userId) !== null;
 }
 catch (Exception $e)
 {
 return false; 
 }
}