structures and classes

Variables of different types can be grouped into a structure or a class.

class person {
public:
     int age;
     int height;
     string surname;
};

person fred, jane;

defines 2 objects of type person each of 3 fields. Fields are accessed using the `.' operator. For example, fred.age is an integer which can be used in assignments just as a simple variable can.

Structure and Class objects may be assigned, passed to functions and returned, but they cannot (by default) be compared, so continuing from the above fragment fred = jane; is possible (the fields of jane being copied into fred) but you can't then go on to do

if (fred == jane)
  cout << "The copying worked ok\n";

- you have to compare field by field.

Classes can contain member functions as well as data. The data can be made private so that other objects can't access it directly.