UML Diagrams MCQs Questions With Answers – Part 5

Test your knowledge and boost your confidence with these multiple-choice quizzes focused on UML diagrams, foundational software engineering concepts, and real-world best practices. Designed for students, developers, and exam candidates, these MCQs offer a quick and effective way to assess your understanding and sharpen your skills.
 
 

1. In UML, what is the role of stereotypes?

A Assign default values to attributes

B Add colors to classes

C Specialize or categorize a UML element

D Represent the database

C

Stereotypes are used to add a specific meaning to a UML element. For example, <<interface>>, <<control>>, <<boundary>>, etc. They are displayed between double angle brackets. Example:
 

2. The activity diagram is often used to represent:

A Class structures

B Organization of use cases

C Composition of a software component

D Logical flow of a process

D

The activity diagram models a control or data flow. Very useful to visualize the steps of a process or business workflow. Example of processing an online order:
 

 

3. What does an arrow between two use cases with the keyword <<include>> represent?

A An error

B An inheritance relationship

C A mandatory inclusion of a behavior

D An optional feature

C

<<include>> means that one use case mandatorily integrates another. Example: “Order a product” includes “Log in”. It is a mandatory reuse.
 

4. What UML keyword is used to represent an optional extension between two use cases?

A <<optional>>

B <<include>>

C <<extend>>

D <<use>>

C

<<extend>> indicates an optional behavior, executed under certain conditions. Example: “Pay with loyalty points” may extend “Place Order”.
 

5. In UML, what does a “component” model?

A A database

B A graphical interface

C A unit test

D A physical part of a software system (module, library, etc.)

D

A component is a reusable or deployable part of a system: it may be a module, an API, a DLL… Modeled in the component diagram. Example:
 

6. Which UML diagram is particularly useful for modeling business processes, workflows, and algorithms?

A Use case diagram

B Sequence diagram

C Class diagram

D Activity diagram

D

The activity diagram uses specific symbols to represent actions, decisions, branches, and parallel flows within a process. Example of an order processing with parallel flows:
 

1- The customer places an order.
2- The system checks the payment.
3- In parallel:
    + Prepare the order
    + Send the invoice
4- Once both are complete, ship the package.

7. What is the standard representation of a class in UML?

A An oval divided into two parts

B A rectangle divided into three parts: name, attributes, methods

C An arrow toward an interface

D A circle with a line

B

A UML class is represented by a rectangle divided horizontally: Class name, attributes, and methods (or operations). Example:
 

8. What is the role of the deployment diagram?

A Show code modules

B Represent the logical flow of a process

C Describe how elements are installed on hardware

D Model the user interface

C

The deployment diagram is a structural diagram that shows how the system is physically deployed: servers, databases, network connections… Example: Classic web application
 

A web client accesses an application server. The application server is connected to a database server.

9. Which UML relationship is often used to model the “is-a” relationship?

A Association

B Composition

C Inheritance (generalization)

D Dependency

C

If we say a class is a specialization of another (e.g., “A Dog is an Animal”), we use an inheritance relationship, also called generalization in UML. Example:
 

We have a class Animal, and a class Dog which is a specialization of Animal. In UML, this is modeled with an arrow with an empty triangle pointing to the parent class.

10. In a class diagram, how is a private attribute represented?

A By prefixing with +

B By prefixing with –

C By prefixing with #

D By writing it in italics

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