Filter validate regexp

[cluelessPHP]

I've been trying to validate with

 FILTER_VALIDATE_REGEXP

I'm trying to allow alphanumeric input but the validation keeps failing when I enter a number

public static function validateUsername($username)
	{
			return strlen($username) >= self::MIN_USERNAME_LENGTH 
			&& (strlen($username)) <= self::MAX_USERNAME_LENGTH
			&& (filter_var($username ,  FILTER_VALIDATE_REGEXP,array('options' => array('regexp' => "/^[a-zA-Z0-9]+$/")) === TRUE);
	}

[laserlight]

filter_var "Returns the filtered data, or FALSE if the filter fails." Therefore, you should have written:

public static function validateUsername($username)
{
    return strlen($username) >= self::MIN_USERNAME_LENGTH
        && strlen($username) <= self::MAX_USERNAME_LENGTH
        && filter_var($username, FILTER_VALIDATE_REGEXP, ['options' => ['regexp' => "/^[a-zA-Z0-9]+$/"]]) !== false;
}

[cluelessPHP]

Thanks