Week 5 notes

Class Diagram

A UML diagram that outlines objects and their relationships in a system.

Purpose of Class Diagrams

They help in system planning, communication, and modeling data structures.

Class Name

The name identifier of a class in a class diagram.

Attributes

Characteristics of the class that define its properties.

Methods

Functions performed by the class, including operations, constructors, queries, and updates.

Class

A logical group of objects with common attributes, relationships, and behaviors.

Object

An instance of a class with a defined role, state, behavior, and unique identity.

Operations in Class Diagrams

Functions or services provided by all instances of a class.

Constructor

A method that creates a new instance of a class.

Query

A method that accesses an object’s state without modifying it.

Update

A method that alters an object’s state.

Class-Scope

A method that applies to a class rather than an individual object.

Association

A relationship among instances of object classes.

Association Role

The name given to the connection between classes within an association.

Multiplicity

Defines how many instances of one class can be associated with another class.

Encapsulation

A concept in object oriented programming where the implementation, data and methods are hidden and access is controlled

What are the four types of operations in a class diagram?

Constructor, Query, Update, Class-Scope.