Using Objects - GridWorld and Java Basics (Unit 2)

Vocabulary flashcards covering GridWorld concepts, Java basics, and object-oriented terminology from the lecture notes.

GridWorld

A Java-based grid environment used in this course to learn object-oriented concepts, featuring Actors like Bugs and Rocks.

CSP-GridWorld.jar

The Java ARchive file that provides the GridWorld library for the project.

GridWorld Workspace.jcw

A GridWorld workspace file opened by JCreator to run a GridWorld project.

Workspace

An IDE area that organizes projects, files, and settings.

Active Project

The project currently selected for building and running.

BugRunner

A program/class that runs GridWorld bugs and demonstrates behaviors.

Grid location

A specific cell in the GridWorld grid, identified by a coordinate.

0-based indexing

Rows and columns are numbered starting at 0.

(row, column) pair

The representation used for a grid location in GridWorld.

Actor

A base class for things that exist on the GridWorld grid and may act.

Bug

A movable Actor subclass representing an insect in GridWorld.

Rock

A non-movable Actor subclass representing a rock obstacle.

Class

A blueprint for creating objects, defining data and behavior.

Object

An instance created from a class, with data and operations.

Parameter

Information required by a method to perform its task.

Argument

Actual data supplied to a method when it is called.

Method

A sequence of instructions an object follows to perform a task.

Return Value

The data produced by a method after it completes.

void

Return type indicating a method does not return a value.

H pattern

A design pattern formed with rocks/flowers for a BugRunner exercise.

java.awt.Color

Java class used to specify colors for objects in GridWorld.

Location

A class representing a grid position, typically with row and column.

Constructor

A special method used to create and initialize an object.

Overloaded

A method with multiple definitions that differ by parameter lists.

world.add(location, actor)

A GridWorld method to place an actor at a given location in the world.

Import

A statement to bring a class or package into scope for use.

Package

A namespace grouping related classes.

Java API

The official Java library of classes and interfaces provided by Oracle.

Accessor method

A method that retrieves data without changing the object.

Mutator method

A method that changes the object's data.

Simple Numeric Types

Primitive numeric types such as int and double.

int

Primitive type for whole numbers.

double

Primitive type for floating-point real numbers.

String

A sequence of characters used to represent text.

Concatenation

Joining two strings into one using the + operator.

length()

String method that returns the number of characters in the string.

Declaration

Statement that introduces a variable by its type and name.

Initialization

Assigning an initial value to a variable.

Assignment operator

The equals sign (=) used to assign a value to a variable.

Identifier

The name assigned to a variable, class, or method; must follow naming rules.

Reserved word

A Java keyword with a special meaning (e.g., int, public).

Java naming conventions

Standards: Class names in PascalCase; variables/methods in camelCase; constants in ALL_CAPS.

Comments

Annotations in code ignored by the compiler to aid human readers; types include single-line, multi-line, and Javadoc.

Javadoc

Documentation-style comments that can be extracted to create API docs; starts with /**.

File Heading

A 6-item Javadoc block at the top of a source file describing the class and collaborators.

Object variables

Variables that hold references to objects (memory addresses), not the objects themselves.

Importing a single class

Syntax: import PackageName.ClassName; to bring one class into scope.

Importing multiple classes from a package

Syntax: import PackageName.*; to bring all classes from a package into scope.

Strings (general)

String is a sequence of characters used to represent text.

Color constants

Predefined colors like Color.GREEN used to set object colors.