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Objects
How objects behave?

| The state of the object changes according to the methods which are applied to it. We refer to these possible sequence of state changes as the behaviour of the object.
| We now have two main concepts of object-orientation introduced, class and object. Object-oriented programming is therefore the implementation of abstract data types or, in more simple words, the writing of classes. At runtime instances of these classes, the objects, achieve the goal of the program by changing their states. Consequently, you can think of your running program as a collection of objects. The question arises of how these objects interact? We therefore introduce the concept of a message in the next section.