Simple C++ program

SIMPLE C++ PROGRAMS

Suppose we would like to display the massage “My name is Komputer, Many greetings to you” on the video screen.

   #include <iostream.h>

   void main ( )  / /  program heading

   {   / / begin

        count  << “My name is Komputer, Many greetings to you”;

   }  / /   end

   The function main ( ) must be placed before the begin statement. It invokes other functions to perform its job. The { symbol or notation is used as the begin statement. The declaration of variables and the type of operations are placed after begin statement. The end statement is denoted by the symbol ‘}’. In C++, the semicolon (;) serves the perpose of a statement terminator rather then a separator.

Statement are terminated by a semicolon and are grouped within braces {…}. Most statements contain expression, sequences of operators, function calls, variable and constants that specify computation.

Variable and function names are of arbitrary lengths and consist of upper and lower case letters, digits and underscore and they may not start with a numeral. All C++ keywords are written in lowercase letters.

Any statement or function within comments are not executable and they are ignored by the compiler. The comments are specified in the following way.

The declaration of the comment statement in the old C style is

/ *  this is a test  * / 

Type any alphanumeric character or statement or function inside the back-slash followed by the symbol  *  (multiplication operator) and should be repeated for termination.

    /*  this is a test

                   program by ravic

                             computer */

The above alphanumeric characters will be ignored by the compiler and is treated as a comment line or remark statement.

      /*    void maim ( )

     {

             cout  <<  “ this is a simple test  \”;

     {

      */

Any executable statement will also be treated as a comment if it is followed by and terminated by the characters / * and * / respectively. The following is the procedure for declaring comments in C++ style.

    The comments may appear anywhere and should begin with the comment delimiter / /.

    For example,

            / / this is a test

            / / this is a new C++ style of remark statement

   There are two advantages of using the comment statement. One, it is easy to understand the variables used in the source program and the other is that it helps in debugging or in tracing the variable by other users.

   The skeleton of a typical C++ program structure is given below:

           program heading

          begin

                    type or variable declaration

                   statement of operation

                  results

        end

   The symbol back-slash (\) followed by a lower case n is used for line feed or a new line. In C++, it is considered as a single character. For Example,

   \n   stands for newline or line feed

A program without using a new line character in the cout stream statement is

    #include <iostream.h>

     void main (void)

     {

         cout   <<  “  My name is Komputer  “;

         cout   <<  “  Many greethings to you   “;

     }

Output of the above program

   My name is Komputer    Many greetings to you