Glossary of Terms

A

abstraction—A process that focuses on what a class or method should do instead of how it will accomplish it.
access modifier—A Java reserved word—public, private, or protected—included in the header of a class or method or in the declaration of a variable that indicates the availability of the class, method, or variable. Omitting an access modifier specifies package access.
accessor method—A method that returns the value of an object’s data field, or instance variable. Also known as a get method or getter.
address—A fixed numeric name associated with each byte of memory.
algorithm—A sequence of steps that solve a problem in a finite amount of time.
alias—A variable that contains the same reference to an object as another variable
analysis of algorithms—The process of measuring the complexity of algorithms.
API—See Java Application Programming Interface.
append—(1) To add characters or a string to the end of a string. (2) To augment a file by adding data to its end.
application—Another term for application program.
application program—A program that enables a user to accomplish a particular task. For example, a word processor is an application program.
application programming interface (API)—See Java Application Programming Interface.
argument—A quantity that appears between the parentheses in a call to a method.
arithmetic expression—An expression whose value is a number that results from the arithmetic operations of addition, subtraction, multiplication, and division.
array—A Java construct that groups items of the same or related data types.
array element—A location in an array. See also array entry.
array entry—The value in an element of an array.
array type—The data type of an array. An array type is a reference type.
array variable—A variable that references and names an array.
ASCII (American Standard Code for Information Interchange)—An integer representation of characters that uses one byte per character. Many programming languages use ASCII, but Java uses Unicode.
assertion—A statement of truth about some aspect of a program’s logic. An assertion can be expressed as a comment or by using an assert statement.
assertion error—The execution time error that occurs when the Boolean expression in an assert statement is false and assertions have been enabled.
assert statement—A statement that enforces an assertion you make in a program. You use such statements during the development of a program, but not as a part of its final logic.
assignment operator (=)—The Java operator used in an assignment statement. The value of the expression on the right side of the assignment operator is assigned to the variable on the left side of the operator.
assignment statement—A Java statement that gives a value to a variable.

B

bag—A collection of items in no particular order. Duplicate items are possible in a bag.
base—The number on which a numbering system is based. For example, familiar decimal numbers have a base of 10.
behavior—An action that an object can take.
best-case time—An estimate of the minimum time an algorithm requires to solve a problem. See also average-case time and worst-case time.
binary operator—An operator that acts on two quantities, or operands. See also unary operator.
bit—A binary digit.
body—(1) The portion of a method definition that follows the header and defines the method’s action. (2) The statements in a loop that are repeated. boolean expression—Either a boolean variable, two variables joined by a relational operator, or two or more boolean expressions joined by logical operators.
boolean expression—Either a boolean variable, two variables joined by a relational operator, or two or more boolean expressions joined by logical operators.
byte—The smallest unit of a computer’s memory. Also a unit of data in memory or on a disk.
bytecode—The form of a Java program produced by the Java compiler and executed by a Java Virtual Machine.

C

call—(n) The statement that begins the execution of a method. (v) To begin the execution of a method. Also known as an invocation (n) and invoke (v).
call by value—A mechanism used to pass an argument to a method whereby the value of the argument is assigned to the argument’s corresponding parameter in the method definition. This value is either a primitive value or a reference.
capacity—See length of an array.
case label—The value that follows the keyword case within a switch statement.
cast—A shortened form of the term type cast.
central processing unit (CPU)—The component of a computer that decodes and executes the instructions of a program stored in memory.
class—A programming construct that describes a group of objects, thereby defining the objects’ data type.
class definition—The Java statements that define a class, including its data fields and methods.
class header—The initial portion of a class that occurs before the first open brace. The header gives the class’s name and can specify an access modifier, a use modifier, a superclass, and one or more interfaces.
class method—See static method.
class-responsibility-collaboration card—See CRC card.
class type—The data type of an object other than an array. A class type is the name of the class used to create the object. For example, a string has a data type of String. See also data type and reference type.
class variable—Another term for static field.
client—The code that uses a class.
client interface—A term used to collectively describe the headers for all public methods of a class, the comments that tell a programmer how to use these public methods, and any publicly defined constants of the class.
code—(n) A general term for statements written in a programming language such as Java. (v) To write statements in a programming language. See also program.
coding—A synonym for programming.
collection—An object that groups other objects, often related by their data type, and provides various services to its client. Typically, a client can add, remove, retrieve, and query the objects in a collection.
command—A specific word written on the command line and used to request the services of an operating system. For example, you can give the command javac to compile a Java program and the command java to execute it.
command line—A line containing a prompt at which a programmer types a command, used to request the services of the operating system.
command-line argument—A value written after a command on the command line. For example, you write the name of the file containing a Java program after the command javac.
comment—Explanatory text placed within Java code to describe its purpose, its ...