Never Have More Than 3 Arguments

Do

printUserInfo(User user) => print('${user.name} ${user.phone} ${user.email} ${user.address}');

Don't

printUserInfo(String name, String phone, String email, String address) {
  print(name + phone + email + address);
}

Tips:

1. When a function seems to need more than two or three arguments, it is likely that some of those arguments ought to be wrapped into a class of their own.
2. Avoid use "+" to concatenate String. Example: name + phone -> '$name $phone'