Intro. to Java Programming

Application Program Interface (API)

Also known as a library, contains predefined classes and interfaces for developing Java programs

Assembler

A program to convert assembly language into machine language

Assembly Language

Low-Level language created to ease the code writing.

Bit

A unit of measurement of information, 0 & 1 create digits known as the binary number system.

Block

Curly braces {}, every class has class blocking that groups the data and methods of the class.

Block Comment

(/) Creates a block comment, computers will read the first (/) and ignore all text until the final (*/). (for multiply line instructions or comments)

Bus

Subsystem of computer components that power and data flow through.

Byte

a sequence of 8 bits (enough to represent one character of alphanumeric data) processed as a single unit of information

Bytecode

Is similar to machine instructions but is architecture neutral and can run on any platform that has a JVM.

Bytecode Verifier

Checks the validity of the Bytecode and to ensure that the Bytecode does not violate Java's security restrictions.

Cable Modem

Uses the cable TV line maintained by the cable company and is generally faster than DSL

Central Processing Unit (CPU)

The part of a computer (a microprocessor chip) that does most of the data processing. 2 parts; Control Unit and Arithmetic/LogicUnit.

Class Loader

Is a part of the Java Runtime Environment that dynamically loads Java classes into the Java Virtual Machine. Usually classes are only loaded on demand. The Java run time system does not need to know about files and file systems because of class loaders.

Comment

Help programmers to communicate and understand the program. (//) single line comment. (/**/) multiply line comment

Compiler

Is a computer program (or set of programs) that transforms source code written in a programming language into another computer language (the target language, often having a binary form known as object code). The most common reason for wanting to transform source code is to create an executable program.

Console

Is an old computer term that refers to the text entry and display device of the computer.

Dot Pitch

The amount of space between pixels, measured in millimeters. The smaller the dot pitch the sharper the display.

Digital Subscriber Line (DSL)

Is a family of technologies that provide Internet access by transmitting digital data over the wires of a local telephone network.

Encoding Scheme

Is a set of rules that govern how a computer translates characters, numbers, and symbols into data the computer can actually work with.

Hardware

In general hardware comprises the visible physical elements of the computer.

High-Level Language

Is a programming language with strong abstraction from the details of the computer. In comparison to low-level programming languages, it may use natural language elements, be easier to use, or may automate (or even hide entirely) significant areas of computing systems (e.g. memory management), making the process of developing a program simpler and more understandable relative to a lower-level language.

Integrated Development Environment (IDE)

Is a software application that provides comprehensive facilities to computer programmers for software development. An IDE normally consists of a source code editor, build automation tools and a debugger.

Interpreter

Changes the source code into machine code for execution.

Java Command

...

Java Language Specification

Is a technical definition of the Java programming language's syntax and semantics.

Java Virtual Machine (JVM)

Iis a virtual machine that can execute Java bytecode. It is the code execution component of the Java platform.

Javac Command

...

Keyword (or reserved word)

Have specific meaning to the compiler and cannot be used for other purposes in the program.

Library

Contains predefined classes and interfaces for developing Java programs.

Line Comment

// is used by programmers to relay information about coding in the program.

Java Development Toolkit (JDK)

The software for developing and running Java programs.

Array

a collection of a fixed number of components wherein all of the components have the same data type

How the components arranged in a one-dimensional array?

In a list form

index

any expression whose value is a nonnegative integer

The array index always starts at...

0

Base address

the address, or memory location, of the first array component

T or F:

A Method can return a value of the type array

True

T or F:

A Method CANNOT return a value of the type array

False

T or F:

The base address of an array is the address of the first array component

True

Algorithm

A step-by-step procedure for calculations. Algorithms are used for calculation, data processing, and automated reasoning.

Assignment Operator (=)

Is the operator used for assignment. Like most other operators in C++, it can be overloaded.

Assignment Statement

Sets and/or re-sets the value stored in the storage location(s) denoted by a variable name, in other words, it copies the value into the variable. In most imperative programming languages, the assignment statement (or expression) is a fundamental construct.

Byte Type

Holds unsigned 8-bit (1-byte) integers that range in value from 0 through 255.

Casting

Is an operation that converts a value of one data type into a value of another data type.

Char Type

Used to represent a single character.

Constant

An identifier whose associated value cannot typically be altered by the program during its execution (though in some cases this can be circumvented, e.g. using self-modifying code). Many programming languages make an explicit syntactic distinction between constant and variable symbols.

Data Type

Simply type is a classification identifying one of various types of data, such as real-valued, integer or Boolean, that determines the possible values for that type; the operations that can be done on values of that type; the meaning of the data; and the way values of that type can be stored.

Declare Variables

Discriptive names that refer to to stored data at for any variable.

Decrement Operators (--)

Are unary operators that add or subtract one from their operand, respectively. They are commonly implemented in imperative programming languages. C-like languages became notorious for featuring two versions (pre- and post-) of each operator with slightly different semantics.

Double type

Refers to a floating point data type that is often more precise than double precision. As with C's other floating point types, it may not necessarily map to an IEEE format.

Encoding

Is a translation between formal languages. For programmers, the most familiar form of encoding is the compilation of a programming language into machine code or byte-code. Conversion between document formats are also forms of encoding. Compilation of TeX or LaTeX documents to PostScript are also commonly encountered encoding processes. Some high-level preprocessors such as OCaml's Camlp4 or Apple Computer's WorldScript also involve encoding of a programming language into another.

Escape Character

Is a character which invokes an alternative interpretation on subsequent characters in a character sequence. An escape character is a particular case of meta-characters. Generally, the judgement of whether something is an escape character or not depends on context.

Expression

A programming language is a combination of explicit values, constants, variables, operators, and functions that are interpreted according to the particular rules of precedence and of association for a particular programming language, which computes and then produces (returns, in a stateful environment) another value. This process, like for mathematical expressions, is called evaluation. The value can be of various types, such as numerical, string, and logical.

Final Keyword

Is used in several different contexts to define an entity which cannot later be changed.

Float Type

Describes a method of representing an approximation of a real number in a way that can support a wide range of values. The numbers are, in general, represented approximately to a fixed number of significant digits (the mantissa) and scaled using an exponent. The base for the scaling is normally 2, 10 or 16. The typical number that can be represented exactly is of the form:

Significant digits × base ^exponent

Floating-Point Number

Describes a method of representing an approximation of a real number in a way that can support a wide range of values. The numbers are, in general, represented approximately to a fixed number of significant digits (the mantissa) and scaled using an exponent. The base for the scaling is normally 2, 10 or 16. The typical number that can be represented exactly is of the form:

Identifier

Are tokens (also called symbols) which name language entities. Some of the kinds of entities an identifier might denote include variables, types, labels, subroutines, and packages.

Increment Operator (++)

Are unary operators that add or subtract one from their operand, respectively. They are commonly implemented in imperative programming languages. C-like languages became notorious for featuring two versions (pre- and post-) of each operator with slightly different semantics.

Incremental Development and Testing

Writing small portions of code (or very simple code, you could write the simplified shell of a program which is complex in theory, but simple and incremental) and then testing those incremental developments.

Int Type

A data type which represents some finite subset of the mathematical integers. Integral data types may be of different sizes and may or may not be allowed to contain negative values. Integers are commonly represented in a computer as a group of binary digits. The size of the grouping varies so the set of integer sizes available varies between different types of computers.

IPO

Also known as the IPO+S Model, is a functional model and conceptual schema of a general system. An IPO chart/table identifies a program's inputs, its outputs, and the processing steps required to transform the inputs into the outputs.

Literal

A notation for representing a fixed value in source code. Almost all programming languages have notations for atomic values such as integers, floating-point numbers, strings, and booleans; some also have notations for elements of enumerated types and compound values such as arrays, records, and objects.

Long Type

Holds signed 64-bit (8-byte) integers ranging in value from -9,223,372,036,854,775,808 through 9,223,372,036,854,775,807 (9.2...E+18).

Narrowing (of Types)

Changes a value to a data type that might not be able to hold some of the possible values. For example, a fractional value is rounded when it is converted to an integral type, and a numeric type being converted to Boolean is reduced to either True or False.

Operands

Is the object of a mathematical operation, a quantity on which an operation is performed.

Operator

Operations which differ in the calling of syntax and/or the argument passing mode from the language's functions. Common examples that differ by syntax are mathematical arithmetic operations, e.g. ">" for "greater than", with names often outside the language's set of identifiers for functions, and called with a syntax different from the language's syntax for calling functions. Common examples that differ by argument passing mode are boolean operations, e.g. a short-circuiting conjunction that only evaluates later arguments if earlier ones are not false, in a language with strict call-by-value functions.

Overflow

Occurs when an arithmetic operation attempts to create a numeric value that is too large to be represented within the available storage space. For instance, adding 1 to the largest value that can be represented constitutes an integer overflow. The most common result in these cases is for the least significant representable bits of the result to be stored (the result is said to wrap). On some processors like GPUs and DSPs, the result saturates; that is, once the maximum value is reached, attempts to make it larger simply return the maximum result.

Postdecrement

Are unary operators that add or subtract one from their operand, respectively. They are commonly implemented in imperative programming languages. C-like languages became notorious for featuring two versions (pre- and post-) of each operator with slightly different semantics.

Postincrement

Are unary operators that add or subtract one from their operand, respectively. They are commonly implemented in imperative programming languages. C-like languages became notorious for featuring two versions (pre- and post-) of each operator with slightly different semantics.

Predecement

Prefix derement, either ++i or --i i=sum of problem.

Preincrement

Prefix increment, either ++i or --i i=sum of problem.

Primitive Data Type

Is either of the following

1. A basic type is a data type provided by a programming language as a basic building block. Most languages allow more complicated composite types to be recursively constructed starting from basic types.

2. A built-in type is a data type for which the programming language provides built-in support.

In most programming languages, all basic data types are built-in. In addition, many languages also provide a set of composite data types.

Pseudocode

Is an informal high-level description of the operating principle of a computer program or other algorithm.

Requirements Specification

A requirements specification for a software system, is a complete description of the behavior of a system to be developed and may include a set of use cases that describe interactions the users will have with the software. In addition it also contains non-functional requirements. Non-functional requirements impose constraints on the design or implementation (such as performance engineering requirements, quality standards, or design constraints) .

Scope of a Variable

Which parts of your program can see or use it. Normally, every variable has a global scope. Once defined, every part of your program can access a variable.

Short Type

Is a term for the abbreviations and slang commonly used with mobile phone text messaging, but sometimes used with other Internet-based communication such as email and instant messaging.

Supplementary Unicode

Are those characters in the Unicode Character Standard outside of the Basic Multilingual Plane (BMP). The BMP consists of the first 64K characters in Unicode. The remaining characters are in the supplementary planes 1-16. Each plane consists of 64K characters.

System Analysis

The study of sets of interacting entities, including computer systems analysis. This field is closely related to requirements analysis or operations research. It is also "an explicit formal inquiry carried out to help someone (referred to as the decision maker) identify a better course of action and make a better decision than he might otherwise have made.

System Design

Is the process of defining the architecture, components, modules, interfaces, and data for a system to satisfy specified requirements. Systems design could be seen as the application of systems theory to product development. There is some overlap with the disciplines of systems analysis, systems architecture and systems engineering.

Underflow

An error condition that occurs when the result of a computation is smaller than the smallest quantity the computer can store.

Unicode

A computing industry standard for the consistent encoding, representation and handling of text expressed in most of the world's writing systems. Developed in conjunction with the Universal Character Set standard and published in book form as The Unicode Standard, the latest version of Unicode contains a repertoire of more than 110,000 characters covering 100 scripts. The standard consists of a set of code charts for visual reference, an encoding method and set of standard character encodings, a set of reference data computer files, and a number of related items, such as character properties, rules for normalization, decomposition, collation, rendering, and bidirectional display order (for the correct display of text containing both right-to-left scripts, such as Arabic and Hebrew, and left-to-right scripts).

UNIX Epoch

POSIX time, is a system for describing instants in time, defined as the number of seconds that have elapsed since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970, not counting leap seconds.

Variable

Is a storage location and an associated symbolic name (an identifier) which contains some known or unknown quantity or information, a value. The variable name is the usual way to reference the stored value; this separation of name and content allows the name to be used independently of the exact information it represents.

Whitespace Character

Is a series of whitespace characters that represent horizontal or vertical space in typography. When rendered, a whitespace character does not correspond to a visible mark, but typically does occupy an area on a page. For example, the common whitespace symbol U+0020 space (HTML: ), also ASCII 32, represents a blank space, used as a word divider in Western scripts.

Widening (of Types)

Changes a value to a data type that can allow for any possible value of the original data. Widening conversions preserve the source value but can change its representation. This occurs if you convert from an integral type to Decimal, or from Char to String.

Who are the comments for, the reader or the compiler?

The Reader

what are the two types of comments?

Single Line & Multiple line

what is the starting point of running a program?

Main

what is the statement terminator in Java?

semicolon (;)

Can reserved words be redefined?

NO

what are blocks?

Pair of braces { } that group program components

how do you display text in a message dialog box?

import javax.swing.JOptionPane; and call the showMessageDialog method

What are syntax errors?

Errors that occur when the rules of the programming language are not followed.

What are run time errors?

They cause the program to terminate abnormally.

example: division by 0, incorrect input by the user

What are logic errors?

When the program does not work as intended.

example: expect output to be 95, but get 60.

Syntax

rules that specify which statements (instructions) are legal

Programming language

a set of rules, symbols, and special words used to construct programs

Semantic rule

meaning of the instruction (means to print to the screen)

!=

not equal to

+

can mean to add or to put two things together