Changes behavior of an object according to his inner state. After calling changing state operation object behaves differently.
(After performing state changing operation)
Example:
An example is for instance girl/boy which before wedding acts differently than after… A wedding is an event which
changes behavior – after wedding a friend turns out to be a completely different person.
Another example may be behavior at a stressed/nervous person. If we ask him about something
when he is nervous he will answer differently than he would answer if the would be relaxed or in a good
humour. In other words the answer depends not only on the question but on the state a person is in at that time.