Four Core Principles of Object-Oriented Programming

These flashcards cover the core vocabulary and concepts of Object-Oriented Programming as outlined in the lecture.

Encapsulation

The principle of hiding the details about how a class works.

Inheritance

A concept where a child class acquires properties (variables and methods) from a parent class.

Abstraction

The principle of focusing on what a thing does, not how it does it.

Polymorphism

The ability to present the same interface for different underlying forms (data types).

Class

A blueprint or data type that you create.

Object

An instance (example) of a class, or a variable of the class data type.

New

The keyword used to create a new object.

Constructor

A method type used to create an object; called when you create a new object.

Setter

A method type used to change a variable, also called a mutator.

Getter

A method type used to see the value of a variable, also called an accessor.

Iterator

A method type that includes a loop, often used to view data.

Private Variables and Public Getters/Setters

The mechanism used to accomplish encapsulation.

Data Safety

The reason we use encapsulation to ensure users interact with the class only in particular ways.

Public Access Modifier

Means the variable or method can be used outside of the class.

Private Access Modifier

Means the variable or method can only be used inside of the class.

Protected Access Modifier

Means the variable or method is accessible within the class and by derived classes.

Class Variable

A variable that is shared among all objects and exists independently of any single object.

Static

The keyword used to create a class variable.

Extends

The keyword used to accomplish inheritance.

Code Reuse

The primary reason we use inheritance so we do not have to duplicate code.

Base Class

The parent class in an inheritance relationship.

Derived Class

The child class in an inheritance relationship.

Super

The keyword used to access methods and variables from the parent (base) class.

Abstract Class

A class that cannot be used to create an object but can have subclasses.

Interface

A type of abstract class that only contains empty methods.

Implements

The keyword used when a class wants to use an interface.

Package

A grouping (like a folder) of related classes and interfaces used to organize code.