Header Files and Standerd of functions

 HEADER FILES

A header files contains definition, global variable declarations, and initialization by all the file in a program. Header files are not compiled separately. The header file can be included in the program using the macro definition #include command. A header file can be declared as a first line in any C++ program. For example, the slandered input/output (stdio.h) header file contains the macro definitions and functions needed by the program input/output statements.

   The header file can be declared in one of the following ways:

           #include <iostream.h>

                    or

        #include   “iostream.h”

STANDARD FUNCTIONS

Standard libraries are used to perform some predefined operations on characters, strings etc. The standard libraries are invoked using different names such as library functions, built in functions or predefined functions. As the term library function indicates, there are a great many of them, actually they are not part of the language. Many facilities that are used in C++ programs need not be part of the C++ language. Most of the C++ compilers support the following standard library facilities.

·        operations on characters

·        operations on strings

·        mathematical operations

·        storage allocation procedures

·        input/output operations