Detailed implementation of PHP input information validator during registration_PHP tutorial

/**
 * Validator for Register.
 */
final class RegisterValidator {
private function __construct() {

}
/**
     * Validate the given username, password, repeat_password and email.
     * @param $username, $password, $repeat_password and $email to be validated
     * @return array array of {@link Error} s
    */
public static function validate($username, $password, $repeat_password, $email) {
$errors = array();
$username = trim($username);
        $password = trim($password);
                                                                                                                                                    (strlen($username)<3) {
                                                                                                                                                                               >30) {
                                                                                                                                                                                                                                                    z]+$/',substr($username, 0, 1))) {
                 $errors[] = new Error('username', 'Username must start with a letter.');
                                                                                                             (!preg_match('/^[A-Za-z0-9_]+$/', $username)) {
        $errors[] = new Error('username', 'Username can only be letters and numbers and a combination of underscores ( _ ). ');
        } elseif (!$password) {
                 $errors[] = new Error('password', 'Password cannot be empty. ');
          } elseif (strlen($password)                   6) { elseif (strlen($password)>30) {
                     $errors[] = new Error('password', 'The password cannot exceed 30 characters.');
                                         ^[A-Za-z0-9!@#\$%\^&\*_]+$/', $password)) {
                     $errors[] = new Error('password', 'Password only It can be a combination of numbers, letters, or characters such as !@#$%^&*_ '); ('password', 'The password entered twice is inconsistent.');
           } elseif (!Utils::isValidEmail($email)) {
                      $errors[] = new Error('email', 'Email format Wrong. ');
} else {
username));
if ($user) {
$errors[] = new Error('username', 'The username has already been used.');
}

$ user = null;
// check whether email being used or not
$user = $dao->findByEmail(trim($email));
if ($user) {
$errors [] = new Error('email', 'This email address has been registered. ');
}
}
} return $errors;
}
}
?>


2、在注册页面进行调用

3.代码中Error类用于记录验证时的错误信息