Unit 2: Programming Languages

Vocabulary terms and definitions covering the fundamental concepts of Object Oriented Programming and the Greenfoot Java environment.

OOP (Object Oriented Programming)

Programming based on collections of objects that interact with each other.

Object

An instance of a class that can be a data structure, a variable, or a function with an allocated memory location.

Class

An entity that serves as a template or set of instructions to determine how an object will behave and what it will contain.

Methods

An action or behaviour that an object is able to perform.

Encapsulation

The process of wrapping data and the code that operates on it into a single entity, placing variables and methods inside the class.

Abstraction

The process of hiding non-essential features and showing only the essential features.

Inheritance

A concept where a new (derived) sub-class inherits the states and behaviours of an existing (base) super class.

Polymorphism

The concept that allows actions to act differently based on the object performing the action.

Conceptual Advantage (OOP)

An advantage where program objects are modelled on real-world objects.

Modularity (OOP)

The ability to write and maintain source code for an object independently of the source code for other objects.

Code re-use

The ability to use existing objects in other programs, allowing specialists to implement, test, and debug complex objects.

Debugging (OOP Advantage)

The ability to replace a problematic object with one that functions correctly without disrupting the entire system.

Greenfoot

A Java interactive development environment used for developing two-dimensional graphical applications like simulations and interactive games.

Class Variables

Attributes shared in common among all objects of a class.

Class Methods

Methods that act on attributes of the whole class through class variables and cannot access instance variables.

Instance Variables and Methods

Features of a class that are object specific rather than shared by the entire class.

Parameter Passing

The practice of moving data into methods, which can be implemented 'by value' or 'by reference'.

Actors

Objects used within the Greenfoot environment that can be moved, added, or removed from worlds.