This lecture considers the different types of relationship that can exist between classes, and looks at their representation in UML and code. It starts with association, which expresses a collaboration between classes, before moving on to consider composition and aggregation, which represent the relationship between a ‘whole thing’ and its component parts.
The bulk of the lecture focuses on inheritance as an expression of the ‘is a kind of’ relationship. The details of how inheritance works in Java are explored, using a small example.
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