Domain Modeling with UML Class Diagrams

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Questions and Answers

Within a UML Domain Class Notation, what convention is ALWAYS followed for class names?

Class names are written in lowercase.
Class names are written in _italics_.
Class names are always capitalized. (correct)
Class names are written in camelback notation.

In domain modeling, what critical distinction defines a Domain Model Class Diagram?

It includes only software classes with attributes and associations.
It includes both classes and interfaces from the user interface.
It includes only classes from the problem domain, excluding any software classes or methods.
It includes classes from the problem domain and software classes with methods. (correct)

How does the concept of an 'Association Class' enhance domain models?

By storing additional information about the relationship itself, beyond just connecting objects.
By replacing conventional classes with more dynamic, behavior-rich entities.
By removing the need for direct relationships between entities, simplifying the diagram. (correct)
By uniquely connecting objects directly, without the possibility of additional attributes.

In the context of multiplicity in UML diagrams, what does the notation '1..*' signify?

One or more instances (C) Signup and view all the answers

When is it most appropriate to use an 'Association Class' in domain modeling?

To avoid creating additional classes in the domain model. (B) Signup and view all the answers

In a domain model for a university's course enrollment system, how would you represent the grade a student receives in a course, considering that the grade is specific to the student's enrollment in that particular course section?

As an attribute of an association class linking 'Student' and 'CourseSection'. (C) Signup and view all the answers

In the context of generalization and specialization, what is a key characteristic of an 'abstract class'?

It represents a concrete entity in the domain model. (B) Signup and view all the answers

What is the significance of 'camelback notation' in UML domain class diagrams?

It indicates that the class is abstract. (D) Signup and view all the answers

Which statement accurately differentiates between 'Aggregation' and 'Composition' in the context of whole-part relationships?

Both aggregation and composition imply that the part can exist independently of the whole. (A) Signup and view all the answers

How is inheritance visually represented in a UML class diagram?

A dashed line with an open circle. (C) Signup and view all the answers

Considering a scenario where a 'Customer' can place multiple 'Orders', and each 'Order' is placed by exactly one 'Customer', with each order containing 'OrderItems', how would you represent the multiplicity between 'Customer' and 'Order'?

0..* to 1 (B) Signup and view all the answers

In domain modeling, attributes are associated with classes. What does the notation custNumber {key} indicate about the `custNumber` attribute?

The attribute is a calculated value. (B) Signup and view all the answers

Why are domain model classes not yet considered software classes?

They are still in the requirements phase and don't have methods yet. (B) Signup and view all the answers

In a UML diagram, when do we call a class 'concrete'?

When it only contains attributes. (C) Signup and view all the answers

What is the primary purpose of a domain model class diagram?

To visualize the classes and their relationships within a system. (B) Signup and view all the answers

How does the 'association class' concept address limitations of the use of standard associations within UML class diagrams?

It simplifies complex relationships by removing the need for intermediate classes. (B) Signup and view all the answers

What is the impact of modifying the multiplicity from '1' to '1..*' on the relationship between two entities in a domain model?

It allows instances of one entity to be associated with one or more instances of the other entity. (B) Signup and view all the answers

When modeling a music library, a `Song` can belong to many `Playlist`s, and a `Playlist` can contain many `Song`s. If you want to store additional data relating to when a song was added to a specific playlist, what would be the most appropriate modeling choice?

Add the <code>dateAdded</code> field to the <code>Playlist</code> class. (C) Signup and view all the answers

In the context of generalization/specialization, consider a `Vehicle` class with specialized subclasses like `Car` and `Truck`. If `Vehicle` has an attribute `numberOfWheels`, and `Car` and `Truck` inherit from `Vehicle`, what design principle does this reflect?

Abstraction, where <code>Vehicle</code> hides the complexity of <code>Car</code> and <code>Truck</code>. (C) Signup and view all the answers

You are modeling a system for a library. A `Library` contains multiple `Book`s. If the `Library` is closed down, the `Book`s can still exist and be transferred to other libraries. How would you model this relationship?

Generalization, with <code>Book</code> inheriting from <code>Library</code>. (B) Signup and view all the answers

Given a scenario of modeling `Brain` and `Person`. A `Brain` is irrevocably a part of a `Person`, and cannot exist independently. When the `Person` ceases to exist, so does the `Brain`. How can you create a UML diagram to represent this?

Use aggregation, the <code>Brain</code> can continue to exist. (B) Signup and view all the answers

For a domain model class diagram in a library management project, what are the key elements to model the relationship between a library branch and its books, considering actions, attributes and multiplicity?

A class for library branch, a class for books, attributes for loan durations and a composition relationship that reflects books are an integral part of the branch. (A) Signup and view all the answers

In designing a domain model for an e-commerce system, you notice a need to capture various discounts applicable to different products. Some discounts are applicable to specific product categories, others to individual customers, and some are applicable to multiple cart items. What would be the method to represent this?

Create a single discount attribute within the product class. (C) Signup and view all the answers

When deciding whether what key to assign an association class, what would you not do?

Give the association class a numbered key. (D) Signup and view all the answers

In the context of whole-part relationships, consider a 'Car' and its 'Wheels'. A 'Car' could exist without having all of its 'Wheels' attached (e.g., during maintenance), and 'Wheels' can certainly exist independently of a specific 'Car' (being sold, stored, etc.). How would you best model this relationship?

Association, because there is simply a general relationship between Car and Wheel. (D) Signup and view all the answers

When constructing a domain model, why is it important to use multiplicity notation to define relationships between classes?

To specify programming language types early in the design process. (B) Signup and view all the answers

In a domain model, what is the primary benefit of using generalization/specialization (inheritance)?

Enabling code reuse and modeling 'is-a' relationships. (B) Signup and view all the answers

In an e-commerce system, how would you best represent a customer's billing and shipping addresses, considering that a customer can have multiple addresses of each type?

Include address attributes directly embedded within the customer class, repeating fields for each address. (B) Signup and view all the answers

You are designing a system for a university. In your domain model, how would you accurately model the scenario of needing more information for the relationship of a student to a particular course, such as enrollment date and grade? Students can also enroll in multiple courses, and courses can have multiple students.

Create an association class <code>Enrollment</code> between <code>Student</code> and <code>Course</code>, including attributes <code>enrollmentDate</code> and <code>grade</code>. (C) Signup and view all the answers

What key consideration dictates the appropriate degree of granularity(how detailed) when creating a domain model?

Balancing capturing essential information and ensuring it aligns perfectly with the requirements. (B) Signup and view all the answers

Flashcards

What is a Class?

A type of classification that describes a collection of objects.

What is a Domain Class?

Classes that describe objects specifically in the problem domain.