Questions and Answers
What is a UML Class Diagram?
A structural UML diagram that represents the structure of an Object-Oriented System by showing the Classes and Relationships between them.
What is a Class in Object-Oriented Programming?
A template for creating objects of a certain type, useful for grouping related features or data.
What does Association refer to in UML?
A relationship between two (or more) classes.
What is Aggregation in UML?
Signup and view all the answers
What does Composition mean in UML?
Signup and view all the answers
How do we represent an Association type relationship in a Class Diagram?
Signup and view all the answers
How do we represent an Aggregation type relationship in a Class Diagram?
Signup and view all the answers
How do we represent a Composition type relationship in a Class Diagram?
Signup and view all the answers
How do we represent an Inheritance type relationship in a Class Diagram?
Signup and view all the answers
How would I represent that Class A realizes the Interface B?
Signup and view all the answers
How would I represent a multiplicity of 2 to many?
Signup and view all the answers
How would I show that a class has a private attribute called name that is a String type?
Signup and view all the answers
How would I show that a class has a public attribute called address that is an Address type?
Signup and view all the answers
How would I show that a class has a public method called complexCalculation that returns a double and takes two parameters; a double called alpha and an integer called gamma?
Signup and view all the answers
How would I convert the following attribute into Java code: - favouriteNumber : int
Signup and view all the answers
How would I convert the following attribute into Java code: - ownedCats : List
Signup and view all the answers
How would I convert the following method into Java code: + complexCalculation(alpha: double, gamma: int): double
Signup and view all the answers
How would I convert the following Class into Java code: Animal with a private String attribute called name and a public method makeSound?
Signup and view all the answers
How do I show that a class is an Abstract class or that a method is an Abstract method in a Class diagram?
Signup and view all the answers
How would I convert the following Class into Java code: Animal with a private String attribute called name?
Signup and view all the answers
How would I convert the following into Java code: Flyable with a public method fly()?
Signup and view all the answers
Study Notes
UML Class Diagram
- Represents the structure of an Object-Oriented System, showcasing Classes and their Relationships.
Class
- Serves as a template for creating objects of a specific type.
- Groups related features or data together.
Association
- Indicates a relationship between two or more classes.
Aggregation
- Represents a 'has a' relationship, stronger than Association.
- Example: A Person has an Address, which can exist independently.
Composition
- Represents an ownership relationship, where X 'owns a' Y.
- Implies that Y cannot exist independently as it is part of X.
Relationship Representation in Class Diagrams
- Association: Shown with a solid line connecting classes.
- Aggregation: Depicted with a solid line and an unfilled diamond at one end, next to the aggregating class.
- Composition: Illustrated with a solid line and a filled diamond at one end, indicating ownership.
- Inheritance: Shown with a solid line and an unfilled triangle at one end, adjacent to the superclass.
- Realization of an Interface: Represented with a dashed line connecting the class to the interface.
Multiplicity
- Indicated as "2..*" to represent a cardinality of 2 to many.
Attributes Representation
- Private attribute example:
- name: Stringtranslates toprivate String name;. - Public attribute example:
+ address: Addresstranslates to+ address: Address;.
Method Representation
- Public method example:
+ complexCalculation(alpha: double, gamma: integer): doubletranslates topublic double complexCalculation(double alpha, int gamma) { /* Implementation */ }.
Conversion to Java Code
- Attributes and methods convert into Java code format based on visibility (private/public) and data types.
- Example for class conversion:
- Class
Animalwith attribute- name: Stringand method+ makeSound():-
public class Animal { private String name; public void makeSound(); }
-
- Class
Abstract Classes and Methods
- Abstract classes or methods are indicated by italicized names or labels stating "abstract".
- Example: Abstract class
Animalrepresentation translates into Java.
Flyable Interface
- Represented with just the interface name and method declaration, e.g.,
+ fly().
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge of UML class diagrams with these flashcards. Each card includes key terms and definitions that are essential for understanding object-oriented system design. Perfect for visualizing classes and their relationships in software development.
