Subject: Object Oriented Modeling and Design

Difficulty: Medium

Marks: 4 Marks

(i) Role names: A role name is a name that uniquely identifies one end of an association. It specifies a role of an object of a class which it plays in the association. A role name is written next to the association line near the class that plays the role.

Example:-

(ii) Class:

A Class is a group of objects with similar properties (attributes), common behavior (operation), common relationship to other objects and common semantics.

Example: fruit, student, employee etc.

Notation:

(iii) Qualified association:

Qualified association specifies relation between two object classes and a qualifier. The qualifier is a special attribute that reduces the effective multiplicity of an association. The qualifier distinguishes among the set of objects at the many end of an association. A qualifier is drawn as a small box on the end of the association line near the class it qualifies.

Notation:

(iv) Ordered association:

Usually the objects on the "many" side of an association have no explicit order, and can be regarded as a set. Sometimes the objects on the many side of an association have order. Writing {ordered} next to the multiplicity dot indicates an ordered set of objects of an association.

Notation: