php - Syntax error on return statement

I'm doing this simple website, and I have run into this error:

My function:

function user_exists($username)
{
    $username = sanitize($username);
    $query = mysqli_query($connect, "SELECT COUNT(`user_id`) FROM `users` WHERE `username` = '$username'");
    return (mysqli_result($query, === 0) 1) ? true : false;
}
 ?>

My php error log:

PHP Parse error:  
syntax error, unexpected '===' (T_IS_IDENTICAL) in function on line 6

Line 6 is the return line.

I understand what a syntax error means, but I'm quite sure that the '===' is not the problem.

Answer

Edit : I was only talking about the ternary condition and this answer is false because the mysqli_result() function doesn't exist.

I guess you are trying to do this :

return mysqli_result($query) === 0 ? false : true;

And as Marcel Korpel said, use prepared statements to avoid security flaws.