CC2 1st Quiz

Variables

Variables

Named computer memory locations that hold values

Procedures

Individual operations grouped into logical units, are also called modules, methods, functions, and subroutines

classes

which are blueprints for objects.

objects

which are specific instances of those classes.

applications

that manipulate or use those objects

Object-oriented programs

An extension of procedural programming in which you take a slightly different approach to writing computer programs

Java

Can be run on wide variety of computers ,Does not execute instructions on computer directly , Runs on hypothetical computer known as Java virtual machine (JVM), Developed by Sun Microsystems, Object-oriented language

Java Runtime Environment (JRE)

It is a software package that provides the necessary runtime environment to execute Java applications and applets. The JRE includes the Java Virtual Machine (JVM), along with core classes and libraries required for running Java programs.

Java Virtual Machine (JVM)

Key component of the Java platform that provides an environment for executing Java bytecode. It allows Java applications to be platform independent by providing an abstraction layer between the compiled Java code (bytecode) and the underlying hardware and operating system

Java Development Kit (JDK)

A software package and development environment created by Oracle (previously Sun Microsystems) that provides tools, libraries, and executables necessary for developing, compiling, and running Java applications and applets. It's an essential tool for Java developers as it includes everything they need to create, test, and deploy Java applications

Source code

Programming statements written in high-level programming language

Bytecode

Statements saved in file, Java compiler converts source code into binary program

Java interpreter

Checks bytecode and communicates with operating system, Executes bytecode instructions line by line within Java virtual machine

Applets

are small Java programs that are designed to be embedded within web pages and executed within a web browser, Programs embedded in Web page

Literal string

A series of characters that will appear in output exactly as entered, Written between double quotation marks

Arguments

Pieces of information passed to method

method

The act of sending arguments to a method

public static void main (String[] args)

main methdod

Java identifier

can contain and can only start with only letters, digits, underscores, or dollar sign

Class Declaration/Definition

This is where you define the class name and its visibility (public, private, protected) using access modifiers. The class name should be descriptive and follow naming conventions

Class Identifier

Defines how class can be accessed

Access specifier or Access modifier

Defines the circumstances under which a class can be accessed and the other classes that have the right to use a class

Pascal Casing

Also known as upper camel casing. In java, refers to the convention of capitalizing the first letter of each word in an identifier.

static

Reserved keyword, Means method accessible and usable

void

Use in main() method header, Indicates main()method does not return value when called

Program comments

Nonexecuting statements added to program for documentation, Use to leave notes for yourself or others, Include author, date, class’s name or function

Line comments

Start with two forward slashes (//)

Block comments

Start with forward slash and asterisk (/*), End with asterisk and forward slash (*/)

Javadoc comments

Special case of block comments, Begin with slash and two asterisks (/**), End with asterisk and forward slash (*/)

public class AnyClassName

public static void main(String[] args)

Shell code

Constant

Cannot be changed while a program is running

Literal Constant

Value taken literally at each use

Numeric constant

As opposed to a character or string constant

Unnamed Constant

As opposed to a named one

Variable

Might change while program is running, Named memory location, Can store a value

Data Type

Type of data that can be stored, How much memory item occupies, What types of operations can be performed on data

Primitive Data Type

Simple data type, A fundamental data type that is directly supported by the programming language and represents the simplest and most basic data units

Variable Declaration

Statement that reserves named memory location

Name Variables

Using naming rules for legal class identifiers, Conventionally begin with lowercase letters

Assignment Operator

Equal sign (=), Value to right assigned to variable on left

Initialization

Assignment made when declaring variable

Assignment

__________ made after variable declared

Named Constant

Also known as symbolic constant, Should not change during program execution, Has data type, name, and value, Data type preceded by keyword final

Block of Code

The code contained between a set of curly braces, A data item’s scope is the area in which it is visible to a program and in which you can refer to it using its simple identifier.

Type int

Store integers, or whole numbers

byte • short • long

Variations of the integer type

print() and println()

Can be used alone or in combination with a string

Concatenate

Plus sign (+), Entire expression becomes String when concatenated

Arithmetic Operators

Perform calculations with values in programs • Example of binary operators

Operand

Value used on either side of operator

Integer Division

Integer constants or integer variables, Result is integer, Fractional part of result lost

Associativity of Operators

The associativity of arithmetic operators with the same precedence is left-to-right.

Operator Precedence

Rules for order in which parts of mathematical expression are evaluated, First multiplication, division, and modulus, Then addition or subtraction

Boolean Logic

Based on true-or-false comparisons

Boolean Variable

Can hold only one of two value :true or false

Relational Operator

Also called comparison operator, Compares two items

Floating-Point Number

Contains decimal positions

float

up to six or seven significant digits of accuracy

double

up to 14 or 15 significant digits of accuracy

Significant Digits

Refers to mathematical accuracy of a value

Type Casting

Forces value of one data type to be used as value of another type

char Data Type

Holds any single character, Place character values within single quotation marks

Escape Sequence

Begins with backslash followed by character, Represents single nonprinting character

String

Built-in class, Store and manipulate character strings, _______ written between double quotation marks

Scanner object

Breaks input into units called tokens

System.in Object

Standard input device; normally the keyboard, Access using Scanner class