Object Modeling and Design

Flashcards reviewing key concepts in object modeling, UML, and object-oriented design principles.

Object-Oriented Programming (OOP)

A paradigm based on objects that contain data (attributes, properties) and code (methods, functions). Objects are instances of classes.

Object-Oriented Design (OOD)

The process of using objects and object-oriented programming when designing a software solution.

Object Calling

Objects don’t accept arbitrary calls. Acceptable calls are defined by methods.

Operations, Procedures, Subroutines, and Functions

Another word for Methods

Method Signature

The name, parameters, and types of a method.

Object Interface

The set of method signatures for that object.

Information Hiding

Restricting access to an object's state (attributes) through an interface

Client Object

Object calling the method.

Server Object

Object receiving and executing the call.

Interface

A set of functional properties that a software object provides or requires.

On-demand design

Design based on the needs of the client objects.

Modular Programming

A software design technique that emphasizes separating the functionality of a program into independent, interchangeable modules (packages).

Modules are loose groupings of subprograms and data, while objects encapsulate data

Difference between Modules and Objects

UML (Unified Modelling Language)

A standardized visual language used in software engineering to represent different aspects of a system's structure and behaviour.

Class Diagrams

Represents the structure of a system by showing classes, their attributes, methods, and relationships.

Use Case Diagrams

Illustrate interactions between actors (users or external systems) and the system to achieve specific goals.

Sequence Diagrams

Depict interactions between objects in a scenario or use case over time.

Activity Diagrams

Model the flow of activities or actions within a system or use case.

State Machine Diagrams

Describe the states of an object or system and transitions between those states triggered by events.

Component Diagrams

Show the components of a system and their relationships.

Deployment Diagrams

Visualize the physical deployment of software components across hardware nodes.

Package Diagrams

Organize and structure the elements of a system into logical groupings.

Association

One object accesses the other in some way (i.e. calling a method, accessing an attribute, etc.)

Inheritance (aka generalisation)

An object inherits the properties of another object through class extension; “is a” relationship

Composition

An object references another object as an instance variable; “has a” relationship

Aggregation

Implies the child class can exist without the parent.

Composition

Implies the child class cannot exist without the parent.

Inheritance

Change in the “base” class propagates to the derived class and its client classes.

Composition

More adaptive to change, because change in the “base” class is easily “contained” and hidden from the clients of the front-end class.

Polymorphism

The ability of objects of different classes to be treated as objects of a common superclass.

Compile-time Polymorphism (Static Binding or Early Binding)

Decision on which method to call is made at compile time; Method & operator overloading

Runtime Polymorphism (Dynamic Binding or Late Binding)

Decision about which method to call is made at runtime based on the type of the object; achieved through method overriding and interface implementation.

Duck Typing

An object’s type/class is less important than the methods it defines.

Subtyping

A type of polymorphism where code written for a supertype will work on a subtype; often achieved with inheritance

Ad-hoc polymorphism

A single name or symbol having multiple implementations depending on the arguments.

TDD

Test-Driven Development