Object Orientation in Pike
Programs Within Programs: Object-Oriented Pike
As we have said before, a class is a description of a type of thing. You can clone the class to create objects. Each object is a clone (sometimes called instance) of the class.
A class contains some variables,
which are sometimes called member variables.
The variables are attributes or characteristics of the objects,
and each object will have
its own set of the member variables.
if the class
animal has the member variables
then each animal will have those two variables,
so each animal can have a name and a weight.
A class also contains some methods. (C++ programmers would call them “member functions”.) The methods describe things that the objects can do.
if the class “animal” has the method
then you can call that method in any animal,
to make it eat.
Well, of course it won’t really eat,
since it’s just some data in the computer
and not a real animal.
But the method can change the member variables,
for example by increasing the value of
weight for that animal.