content: extension ExtString on String {
    String capitalize() {
      return "${this[0].toUpperCase()}${substring(1).toLowerCase()}";
    }
  
    bool get isValidEmail {
      final emailRegExp = RegExp(r"^[a-zA-Z0-9.]+@[a-zA-Z0-9]+\.[a-zA-Z]+");
      return emailRegExp.hasMatch(this);
    }
  
    bool get isValidName{
      final nameRegExp = RegExp(r"^\s*([A-Za-z]{1,}([\.,] |[-']| ))+[A-Za-z]+\.?\s*$");
      return nameRegExp.hasMatch(this);
    }
  
    bool get isValidPassword{
      final passwordRegExp =
      RegExp(r'^(?=.*?[A-Z])(?=.*?[a-z])(?=.*?[0-9])(?=.*?[!@#\><*~]).{8,}/pre>');
      return passwordRegExp.hasMatch(this);
    }
  
    bool get isValidPasswordHasSpecialCharacter{
      final passwordRegExp =
      RegExp(r'[!@#$\><*~]');
      return passwordRegExp.hasMatch(this);
    }
  
    bool get isValidPasswordHasCapitalLetter{
      final passwordRegExp =
      RegExp(r'[A-Z]');
      return passwordRegExp.hasMatch(this);
    }
  
    bool get isValidPasswordHasLowerCaseLetter{
      final passwordRegExp =
      RegExp(r'[a-z]');
      return passwordRegExp.hasMatch(this);
    }
  
    bool get isValidPasswordHasNumber{
      final passwordRegExp =
      RegExp(r'[0-9]');
      return passwordRegExp.hasMatch(this);
    }
  
    bool get isValidPhone{
      final phoneRegExp = RegExp(r"^\+?0[0-9]{10}$");
      return phoneRegExp.hasMatch(this);
    }
  }