Java Programming Terminology Glossary

abstract

A Java reserved word that serves as a modifier for classes, interfaces, and methods.

abstract class

A class used in the design of an inheritance hierarchy to specify undefined functionality that must be defined by its descendants. An abstract class cannot be instantiated.

abstract data type (ADT)

A collection of data and the operations that are defined on that data.

abstract method

A method header with no body. The code of an abstract method is defined by the implementing class.

Abstract Windowing Toolkit (AWT)

A graphics package in the Java API that, along with the Swing package, has been replaced by the JavaFX package.

abstraction

The concept of hiding details. If the right details are hidden at the right times, abstraction can significantly help control complexity and focus attention on appropriate issues.

access

The ability to reference a variable or invoke a method from outside the class in which it is declared. Controlled by the visibility modifier used to declare the variable or method.

access modifier

See visibility modifier.

action event

A type of event that indicates the user took some action. An action event is generated by several GUI controls, such as a button when it is pushed.

actual parameter

The value passed to a method as a parameter.

address

(1) A numeric value that uniquely identifies a particular memory location in a computer's main memory. (2) A designation that uniquely identifies a computer among all others on a network.

ADT

See abstract data type.

aggregate object

An object that contains variables that are references to other objects.

alert

A simplified dialog box in JavaFX. There are several types of predefined alerts.

algorithm

A step-by-step process for solving a problem. A program is based on one or more algorithms.

alias

A reference to an object that is currently also referred to by another reference. Each reference is an alias of the other.

analog

A representation that is in direct proportion to the source of the information.

anchor pane

A JavaFX layout pane in which nodes can be anchored to the top, bottom, left side, right side, or center of the pane.

animation

A series of images or drawings that give the appearance of movement when displayed in order at a particular speed.

API

See Application Programming Interface.

applet

A Java program that is linked into an HTML document, then retrieved and executed using a Web browser. JavaFX technology has generally replaced applets.

application

(1) A generic term for any program. (2) A Java program that can be run without the use of a Web browser, as opposed to a Java applet.

Application Programming Interface (API)

A set of classes that defines services for a programmer. Not part of the language itself, but often relied on to perform even basic tasks.

arc

A JavaFX shape that is defined as a portion of an ellipse.

arc type

The type of a JavaFX arc, which may be open, chord, or round.

architectural design

A high-level design that identifies the large portions of a software system and key data structures.

architecture neutral

Not specific to any particular hardware platform. Java code is considered architecture neutral because it is compiled into bytecode and then interpreted on any machine with a Java interpreter.

arithmetic operator

An operator that performs a basic arithmetic computation, such as addition or multiplication.

arithmetic promotion

The act of promoting the type of a numeric operand to be consistent with the other operand.

array

A programming language construct used to store an ordered list of primitive values or objects. Each element in the array is referenced using a numerical index from 0 to N−1, where N is the size of the array.

array element

A value or object that is stored in an array.

array element type

The type of the values or objects that are stored in an array.

ASCII

A popular character set used by many programming languages. ASCII stands for American Standard Code for Information Interchange. It is a subset of the Unicode character set, which is used by Java.

assembly language

A low-level language that uses mnemonics to represent program commands.

assert

A Java reserved word used to establish an assertion about a program for testing purposes.

assignment conversion

Some data types can be converted to another in an assignment statement.

assignment operator

An operator that results in an assignment to a variable. The = operator performs basic assignment.

association

A relationship between two classes in which one uses the other or relates to it in some way.

autoboxing

The automatic conversion from a primitive value to a corresponding wrapper object.

AWT

See Abstract Windowing Toolkit.

base

The numerical value on which a particular number system is based.

base 2

See binary.

base 8

See octal.

base 10

See decimal.

base 16

See hexadecimal.

base case

The condition that terminates recursive processing, allowing the active recursive methods to begin returning to their point of invocation.

base class

See superclass.

behavior

The functional characteristics of an object, defined by its methods.

binary

The base-2 number system. Modern computer systems store information as strings of binary digits (bits).

binary operator

An operator that uses two operands.

binary search

A searching algorithm that requires that the list be sorted.

binary string

A series of binary digits (bits).

binary tree

A tree data structure in which each node can have no more than two child nodes.

binding

The process of associating an identifier with the construct that it represents.

bit

A binary digit, either 0 or 1.

bit shifting

The act of shifting the bits of a data value to the left or right.

bits per second (bps)

A measurement rate for data transfer devices.

bitwise operator

An operator that manipulates individual bits of a value, either by calculation or by shifting.

black-box testing

Producing and evaluating test cases based on the input and expected output of a software component.

block

A group of programming statements and declarations enclosed in braces ( {}).

boolean

A Java reserved word representing a logical primitive data type that can only take the values true or false.

boolean expression

An expression that evaluates to a true or false result, primarily used as conditions in selection and repetition statements.

boolean operator

Any of the bitwise operators AND (&), OR (|), or XOR (^) when applied to boolean operands.

border pane

A JavaFX layout pane that organizes its nodes into five regions: top, bottom, left, right, and center.

boundary values

The input values corresponding to the edges of equivalence categories.

bounds checking

The process of determining whether an array index is in bounds, given the size of the array.

bps

See bits per second.

break

A Java reserved word used to interrupt the flow of control by breaking out of the current loop or switch statement.

browser

A program that retrieves HTML documents and other resources across a network and formats them for viewing.

bug

A slang term for a defect or error in a computer program.

build-and-fix approach

An unwise approach to software development in which a program is created without any significant planning or design.

bus

A group of wires in the computer that carry data between components such as the CPU and main memory.

button

A GUI control that allows the user to initiate an action with a mouse click.

byte

(1) A unit of binary storage equal to eight bits. (2) A Java reserved word that represents a primitive integer type, stored using eight bits in two's complement format.

byte stream

An I/O stream that manages 8-bit bytes of raw binary data.

bytecode

The low-level format into which the Java compiler translates Java source code. The bytecodes are interpreted and executed by the Java interpreter, perhaps after transportation over the Internet.

capacity

See storage capacity.

Cascading Style Sheets (CSS)

A language used to describe the way content looks when presented. CSS is used to format web pages, and is also used in JavaFX to style nodes.

case

(1) A Java reserved word that is used to identify each unique option in a switch statement. (2) The orientation of an alphabetic character (uppercase or lowercase).

case sensitive

Differentiating between the uppercase and lowercase versions of an alphabetic letter. Java is case sensitive; therefore the identifier total and the identifier Total are considered to be different identifiers.

cast

A Java operation expressed using a type or class name in parentheses to explicitly convert and return a value of one data type into another.

catch

A Java reserved word that is used to specify an exception handler, defined after a try block.

CD-Recordable (CD-R)

A compact disc on which information can be stored once using a home computer with an appropriate drive.

CD-ROM

An optical secondary memory medium that stores binary information in a manner similar to a musical compact disc.

central processing unit (CPU)

The hardware component that controls the main activity of a computer, including the flow of information and the execution of commands.

change listener

An object that is set up to respond when an observable value, such as a JavaFX property, is changed.

char

A Java reserved word that represents the primitive character type. All Java characters are members of the Unicode character set and are stored using 16 bits.

character set

An ordered list of characters, such as the ASCII or Unicode character sets. Each character corresponds to a specific, unique numeric value within a given character set.

character stream

An I/O stream that manages 16-bit Unicode characters.

character string

A series of ordered characters. Represented in Java using the String class and string literals such as "hello".

check box

A GUI control that allows the user to set a boolean condition with a mouse click.

checked exception

A Java exception that must be either caught or explicitly thrown to the calling method.

child class

See subclass.

choice box

A GUI control that allows the user to select one of several options from a drop down menu.

class

(1) A Java reserved word used to define a class. (2) The blueprint of an object—the model that defines the variables and methods an object will contain when instantiated.

class diagram

A diagram that shows the relationships between classes, including inheritance and use relationships.

class hierarchy

A tree-like structure created when classes are derived from other classes through inheritance.

class library

A set of classes that define useful services for a programmer.

class method

A method that can be invoked using only the class name. An instantiated object is not required as it is with instance methods.

CLASSPATH

An operating system setting that determines where the Java interpreter searches for class files.