string validation in dart
bool isPasswordCompliant(String password, [int minLength = 6]) {
if (password == null || password.isEmpty) {
return false;
}
bool hasUppercase = password.contains(new RegExp(r'[A-Z]'));
bool hasDigits = password.contains(new RegExp(r'[0-9]'));
bool hasLowercase = password.contains(new RegExp(r'[a-z]'));
bool hasSpecialCharacters = password.contains(new RegExp(r'[!@#$%^&*(),.?":{}|<>]'));
bool hasMinLength = password.length > minLength;
return hasDigits & hasUppercase & hasLowercase & hasSpecialCharacters & hasMinLength;
}