Tutorial on Basic Concepts of C++ Program Part 2

 iostream File:

#include<iostream.h>

1. The Header File iostream should be included at the beginning of all Programs. 
2. It contains declarations for the identifiers Cout , Cin and the << , >> Operators. 
3. Some old versions of C++ use a Header File called iostream.h . 
4. We should use iostream.h if the compiler does not support ANSI C++ Feature.
5. If the compiler support ANSI C++ Feature then we use iostream .

#include<iostream>

 Some Header Files are :

1. <time.h>  contains Function prototypes and types for manipulating the time and date. 
2. <iomanip.h> contains functions prototypes for the Standard Input and Standard output Functions. 
3. <iomanip.h> contains Function prototypes for the stream manipulators that enable formatting of streams of data. 
4. <fstream.h> contains Function prototypes for that performs Input from Files on disk and output to File on disk.

New Header Files included in ANSI C++ : 

1. <algorithm> contains Functions for manipulating data in the Standard Library containers
2. <iterator> contains classes for manipulating data in the Standard Library containers. 
3. <string> contains the definition of class string from the Standard Library.

Namespace :

1. Namespace is a new concept introduced by the ANSI C++ standard commitee. 
2. This defines a scope for the identifiers that are used in a program. 
3. For using the identifiers defined in the namespace scope we must include the using directory.

Using namespace std ;

• Here, std is the namespace where ANSI C++ standard class Libraries are defined. 
• All the ANSI C++ Programs must include this directive. 
• using and namespace are the New keywords of C++.

Comments:

• C++ introduces a new comment symbol // (double slash). 
• Comments start with a double slash symbol and terminates at the end of the line. 
• A comment may start anywhere in the Line. 
• Note that There is no closing symbol. 
• The double slash comment is basically a single line comment. Multi Line comments can be written as

// Features of C++,   // Important Concepts and     // Programming Functions .

• The C comment symbol   /*   */   are more suitable for Multi Line comment.

/*          Features of C++ , Important Concepts and           Programming Functions.    */