variables in c++

Variable A variable is a symbolic name for a memory location in which data can be stored and subsequently recalled. Variables are used for holding data values so that they can be utilized in various computations in a program. All variables have two important attributes: A type which is established when the variable is defined (e.g., integer, real, character)....

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How C++ Compilation Works

Compiling a C++ program involves a number of steps : First, the C++ preprocessor goes over the program text and carries out the instructions specified by the proprocessor directives (e.g., #include). The result is a modified program text which no longer contains any directives. Then, the C++ compiler translates the program code. The compiler may...

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Compiling C++ Program

Compiling C++ Program $ CC hello.cc $ a.out Hello World $ Annotation The command for invoking the AT&T C++ translator in a UNIX environment is CC. The argument to this command (hello.cc) is the name of the file which contains the program. As a convention, the file name should end in .c, .C, or .cc. (This ending may be different...

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Simple C++ Program

A Simple C++ Program #include <iostream.h> int main (void) { cout << "Hello World\n"; } Annotation This line uses the preprocessor directive #include to include the contents of the header file iostream.h in the program. Iostream.h is a standard C++ header file and contains definitions for input and output. This line defines...

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exceptions in java

Exceptions Programmers in any language endeavor to write bug-free programs, programs that never crash, programs that can handle any circumstance with grace and recover from unusual situations without causing a user any undue stress. Good intentions aside, programs like this don’t exist. In real programs, errors occur because programmers didn’t anticipate...

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java.io package

An overview of the java.io package Introduction This section introduces the java.iopackage. Here are some basic points about I/O: * Data in files on your system is called persistent data because it persists after the program runs. * Files are created through streams in Java code. * A stream is a linear, sequential flow of bytes of input or output...

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Java2D Shapes

Java2D Shapes Next, we present several java2D shapes from package java.awt.geom, including Ellipse2D.Double, Rectangle2D.Double, RoundRectangle2D.Double, Arc2D.Double and Line2D.Double. Note the syntax of each class name. Each of these classes represents a shape with dimensions specified as double-precision floatingpoint values. There is a...

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Java2D

The Java2D API The java2D API provides advanced two-dimensional graphics capabilities for programmers who require detailed and complex graphical manipulations. The API includes features for processing line art, text and images in packages  java.awt,  java.awt.image, java.awt.color,  java.awt.font,  java.awt.geom,  java.awt.print...

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drawing polygons in java

Drawing Polygons and Polylines polygen are multisided shapes. Polylines are a series of connected points. Graphics methods for drawing polygons and polylines The program of draws polygons and polylines using the methods and constructors Lines 18 through 20 create two int arrays and use them to specify the points for Polygon poly1. The Polygon constructor...

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drawing arcs in java

Drawing Arcs An arc is a portion of a oval. Arc angles are measured in degrees. Arcs sweep from a starting angle the number of degrees specified by their arc angle. The starting angle indicates in degrees where the arc begins. The arc angle specifies the total number of degrees through which the arc sweeps. The left set of axes shows an arc sweeping...

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drawing lines,Rectangles and Ovals in java

Drawing Lines, Rectangles and Ovals This section presents a variety of Graphics methods for drawing lines, rectangles and ovals. For each drawing method that requires a width and height parameter, the width and height must be nonnegative values. Otherwise, the shape will not display. public void drawLine( int x1, int y1, int x2, int y2 )...

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font controller pattern in java

Font Control Most font methods and font constants are part of class Font. Some methods of class Font and class Graphics are Class Font’s constructor takes three arguments—the font name, font style and font size. The font name is any font currently supported by the system where the program is running, such as standard Java fonts Monospaced, SansSerif...

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color control java

Color Control colors  enhance the appearance of a program and help convey meaning. For example, a traffic light has three different color lights—red indicates stop, yellow indicates caution and green indicates go. Class Color defines methods and constants for manipulating colors in a Java program. Color Constant Color...

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paint method in java

paint method The Paint is seldom called directly by the programmer because drawing graphics is an event-driven process. When an applet executes, the paint method is automatically called (after calls to the JApplet’s init and start methods). For paint to be called again, an event must occur (such as covering and uncovering the applet). Similarly,...

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graphics in java

Graphics Contexts and Graphics Objects A Java graphics context enables drawing on the screen. A Graphics object manages agraphics context by controlling how information is drawn. Graphics objects contain methods for drawing, font manipulation, color manipulation and the like. Every applet we have seen in the text that performs drawing on the screen...

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prepared statements java

Using Prepared Statements Sometimes it is more convenient or more efficient to use a PreparedStatement object for sending SQL statements to the database. This special type of statement is derived from the more general class, Statement, that you already know. When to Use a PreparedStatement Object: If you want to execute a Statement object many...

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creating jdbc statements

Creating JDBC Statements A Statement object is what sends your SQLstatement to the DBMS. You simply create a Statement object and then execute it, supplying the appropriate execute method with the SQL statement you want to send. For a SELECT statement, the method to use is executeQuery . For statements that create or modify tables, the method...

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creating tables in java

Creating a Table make money First, we will create one of the tables in our example database. This table, COFFEES , contains the essential information about the coffees sold at The Coffee Break, including the coffee names, their prices, the number of pounds sold the current week, and the number of pounds sold to date. The table COFFEES , which we...

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establishing a connection to sql server

Establishing a Connection The first thing you need to do is establish a connection with the DBMS you want to use. This involves two steps: (1) loading the driver and (2) making the connection. Loading Drivers Loading the driver or drivers you want to use is very simple and involves just one line of code. If, for example, you want to use the JDBC-ODBC...

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jdbc settings oracle

Setting Up a Database We will assume that the database COFFEE BREAK already exists. (Creating a database is not at all difficult, but it requires special permissions and is normally done by a database administrator.) When you create the tables used as examples in this tutorial, they will be in the default database. We purposely kept the size and...

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jdbc get started

Getting Started The first thing you need to do is check that you are set up properly. This involves the following steps: 1. Install Java and JDBC on your machine. To install both the Java tm platform and the JDBC API, simply follow the instructions for downloading the latest release of the JDK tm (Java Development Kit tm ). When you download the...

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jdbc tutorial

JDBC Basics In this lesson you will learn the basics of the JDBC API. We start by giving you set up instructions in Getting Started , Setting Up a Database , and Establishing a Connection . The next sections discuss how to create and update tables, use joins, transactions and stored procedures. The final sections give instructions on how to complete...

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Generics java

Defining Simple Generics Here is a small excerpt from the definitions of the interfacesList and Iterator in package java.util: public interface List { void add(E x); Iterator iterator(); } public interface Iterator { E next(); boolean hasNext(); } This should all be familiar, except for the stuff in angle brackets. Those are the declarations of...

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Inheriting Instance Fields and Methods

Inheriting Instance Fields and Methods When you form a subclass of a given class, you can specify additional instance fields and methods. In this section we will discuss this process in detail. When defining the methods for a subclass, there are three possibilities. 1. You can Override methods from the superclass. If you specify a method with the same...

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inheritance in java

Inheritance Inheritance is a mechanism for enhancing existing classes. If you need to implement a new class and a class representing a more general concept is already available, then the new class can inherit from the existing <a href="http://573120-9-kcfw4skv8zbsfteak.hop.clickbank.net/" target="_top">class</a>. For example, suppose...

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return statement in java

 return statement returns control to the invoker of a method or constructor . ReturnStatement: return Expressionopt ; A return statement with no Expression must be contained in the body of a method that is declared, using the keyword void, not to return any value , or in the body of a constructor . A compile-time error occurs if a return...

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continue Statement in java

The continue Statement “Your experience has been a most entertaining one,” remarked Holmes as his client paused and refreshed his memory with a huge pinch of snuff. “Pray continue your very interesting statement.” A continue statement may occur only in a while, do, or for statement; statements of these three kinds are called iteration statements. Control...

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Break statement in java

The break Statement A break statement transfers control out of an enclosing statement. BreakStatement: break Identifieropt ; A break statement with no label attempts to transfer control to the innermost enclosing switch, while, do, or for statement of the immediately enclosing method or initializer block; this statement, which is called the break...

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For Statement in java

for Statement ForStatement: 1)BasicForStatement 2)EnhancedForStatement The for statement has two forms: • The basic for statement. • The enhanced for statement The basic for Statement The basic for statement executes some initialization code, then executes an Expression, a Statement, and some update code repeatedly until the value of the Expression...

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do statement java

The do Statement “She would not see it,” he said at last, curtly, feeling at first that this statement must do without explanation. The do Statement  executes a Statement and an Expression repeatedly until the value of the Expression is false. Syntax: do Statement while ( Expression ) ; The Expression must have type boolean or Boolean, or...

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C Tutorial

Buy 1 Get 1 Free Xmas Sale c tutorial for beginner .this site can be providing basic lesson for beginner Lesson 1 Identifiers Under Line Comments   Formatting Text Expression Lesson 2 reserved words printf conversion specifiers primitive data types preprocessor directives Input...

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