Introduction to Java Programming - Chapter 1

bit

A binary digit- a 0 or 1.

main class

A class that stores the main method.

block comment

A comment type enclosed in /* and */ on one or several lines in the source code.

network interface card (NIC)

A device to connect a computer to a local area network (LAN). The LAN is commonly used in business, universities, and government organizations.

statement

A line of code that represents an action or sequence of actions.

Java Virtual Machine (JVM)

A machine that runs Java bytecode. It is called virtual because it is usually implemented in software, rather than hardware.

Bytecode verifier

A program in the JVM that checks the validity of the bytecode and ensures that the bytecode does not violate Java's security restrictions.

operating system (OS)

A program that controls and manages a computer's activities.

assembler

A program that translates assembly-language programs into machine code.

source code

A program written in a programming language, such as Java.

high-level programming language

A programming language that is English-like and easy to learn.

block

A sequence of statements enclosed in braces.

Application Program Interface (API)

A set of classes and interfaces that can be used to develop Java programs.

machine language

A set of primitive instructions built into every computer. The instructions are in the form of binary code.

central processing unit (CPU)

A small silicon semiconductor chip with millions of transistors that execute instructions.

compiler

A software program that translates source code into a machine language program.

pixel

A tiny dot that forms part of an image on a screen.

keyword (reserved word)

A word defined as part of the Java language that has a specific meaning to the compiler, and cannot be used for other purposes in the program.

Just-in-Time compiler

Capable of compiling each bytecode once, and then reinvoking the compiled code repeatedly when the bytecode is executed.

line comment

Comments preceded by two slashes.

Java Development Toolkit (JDK)

Defines the Java API and contains a set of command line utilities, such as javac (compiler) and java (interpreter).

wildcard import

Imports an entire package.

binary numbers

Numbers consisting of 1s and 0s.

hexadecimal numbers

Numbers with radix 16.

interpreter

Software for interpreting and running Java bytecode.

Integrated Development Environment (IDE)

Software that helps programmers write code efficiently. IDE tools integrate editing, compiling, building, debugging, and online help in one graphical user interface.

specific import

Specifies a single class in an import statement.

resolutions

Specifies the number of pixels per square inch. The higher the resolution, the sharper and clearer the image is.

memory

Stores data and instructions for the CPU to execute.

dot pitch

The amount of space between pixels. The smaller the dot pitch, the better the display.

javac command

The command to invoke the compiler to compile the Java source code program from the command line.

java command

The command to invoke the interpreter to run the Java program from the command line.

software

The invisible instructions that control the software and make it work.

. class file

The output for a Java compiler. This contains the byte code for the class.

storage device

The permanent storage for data and programs. Memory is volatile because the information is lost when the power is off. Programs and data are stored in secondary storage and moved to memory when the computer actually uses them.

hardware

The physical aspects of a computer than can be seen.

bytecode

The result of compiling Java source code. Bytecode is machine independent and can run on any machine that has a Java runtime environment.

.java file

The source code for a java program. This may contain one or more Java classes and interfaces. This can be created using a text editor or a Java IDE.

comment

These document what a program is and how it is constructed. They are not programming statements and are ignored by the compiler.

modem

Uses a phone line and can transfer data.

DSL (digital subscriber line)

Uses a phone line and can translate data in a speed 20 times faster than a regular modem.

cable modem

Uses the TV cable line maintained by the cable company. A cable modem is as fast as a DSL.

class loader

When executing a Java program, the JVM first loads the bytecode of a class to memory using a program called the class loader. If your program uses other classes, the class loader dynamically loads them just before they are needed.