UML - Class Diagrams

What is the difference between Agile and Waterfall methodologies?

Waterfall is linear, with clearly defined phases, and is suited for projects with concrete timelines. Agile is iterative, using sprints, and is designed for projects with less defined constraints.

What is a model in the context of software engineering?

A model is an abstract representation of a system that helps answer questions and aids in understanding, communication, and sharing mental models.

What is UML?

UML (Unified Modelling Language) is a visual language used for developing software systems.

What is the difference between As-Is and To-Be models?

An As-Is model describes a system as it currently is, while a To-Be model describes how the system will be in the future.

What does class modelling focus on?

Class modelling focuses on the general structure of a system, determining how it will satisfy its requirements.

What are the different visibility modifiers in UML class diagrams?

• private: Inaccessible from outside the class
• public: Accessible from outside the class
• protected: Accessible to the class and its subclasses

How do you define attributes in a UML class diagram?

Attributes are defined with the syntax: visibility attribute_name[multiplicity ordering] : type = initial_value.

How do you define operations in a UML class diagram?

Operations are defined with the syntax: visibility operation_name(parameter list): return_type → kind name: type = default_value.

What is the difference between binary and n-ary associations in UML?

Binary associations involve two classes, while n-ary associations relate three or more classes.

What is aggregation in UML?

Aggregation is a weak "has-a" relationship where the lifecycle of the contained object does not depend on the container.

What is composition in UML?

Composition is a strong "contains-a" relationship where the lifecycle of the contained object depends on the container.

What is generalization in UML?

Generalization is when a more specific element inherits attributes, relationships, and operations from a more general element.

What are stereotypes in UML?

Stereotypes extend the meaning of model elements with additional semantics, such as <<interface>>, <<abstract>>, <<boundary>>, <<entity>>, and <<control>>.

What is the purpose of the realisation/implementation relationship in UML?

The realisation/implementation relationship defines how an interface or abstract class is implemented by a concrete class.

What are the steps involved in an online assignment example?

1. Lecturer creates an assignment
2. Student submits coursework
3. Students and lecturers can view assignments
4. Students receive confirmation for submission
5. Lecturers sometimes grade the coursework
6. System prints confirmation.

What does a use case diagram do?

A use case diagram identifies potential classes and their interactions in a system.

What is the purpose of a class diagram?

A class diagram identifies classes and their associations within the system. \