Final Material - System Modelling Using UML Diagrams

Question 1

What is the difference between structural and behavioural UML diagrams?

Answer 1

Structural diagrams present a static view of the system using objects, attributes, operations, and relationships
Behavioural diagrams present a dynamic view of the system showing collaborations among objects and changes to the internal state of objects

Question 2

What is the purpose of a class diagram?

Answer 2

To show the classes in a system and the relationship between the classes

Question 3

What is an association relationship in UML class diagrams?

Answer 3

Shows a has-a relationship between classes. It is represented by a line sometimes with an arrow and a name for the relationship which is usually a verb

Question 4

What is an aggregation relationship in UML class diagrams?

Answer 4

A part-whole relationship, subset of association. The part may exist independent of the whole and can belong to more than one whole. It is represented with a hollow diamond at the “whole” end

Question 5

What is a composition relationship in UML class diagrams?

Answer 5

A part-whole relationship, subset of association. Stronger version of aggregation. A part can not exist independent of the whole and can only belong to one whole. It is represented by a filled diamond at the “whole” end

Question 6

What is multiplicity in UML class diagrams?

Answer 6

Defines the number of times a class is associated with another class

Question 7

What is a generalization relationship in UML class diagrams?

Answer 7

Represents a parent-child relationship. Allows us to group characteristics into general classes and then make more specified forms. Represented by and open triangle pointing to the generalized class

Question 8

What is the purpose of a sequence diagram?

Answer 8

Used to model interactions between actors and objects within a system

Question 9

What is an activation box in a sequence diagram?

Answer 9

They indicate when an object is active or inactive

Question 10

What is an alternative frame in a sequence diagram?

Answer 10

Provide a choice between two alternative sequences of actions (like else-if block)

Question 11

What is a lifeline in a sequence diagram?

Answer 11

The path the program takes between each actor and the objects