Password strength check in PHP [closed]

Question

I am trying to create a password check script. I already have checks for email (for not allowed characters) like this:

  public function checkEmail($email)
  {
    if (filter_var($email, FILTER_VALIDATE_EMAIL))
      return true;
    else
      return false;   
  }

So I am looking for a password validation function that checks passwords have at least one alphanumeric character, and one numeric character, and a minimum of 8 characters, and also provides error messages.

Answer 1

public function checkPassword($pwd, &$errors) {
    $errors_init = $errors;

    if (strlen($pwd) < 8) {
        $errors[] = "Password too short!";
    }

    if (!preg_match("#[0-9]+#", $pwd)) {
        $errors[] = "Password must include at least one number!";
    }

    if (!preg_match("#[a-zA-Z]+#", $pwd)) {
        $errors[] = "Password must include at least one letter!";
    }     

    return ($errors == $errors_init);
}

Edited version of this: http://www.cafewebmaster.com/check-password-strength-safety-php-and-regex