6.1: The Rules of the Model
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- 39598
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The object model is based on a set of simple rules that are applied uniformly.
The rules are as follows:
Rule 1. Everything is an object.
Rule 2. Every object is an instance of a class.
Rule 3. Every class has a superclass.
Rule 4. Everything happens by sending messages.
Rule 5. Method lookup dynamically follows the inheritance chain.
Let us look at each of these rules in some detail.