Q1 Define Structure of C program and explain the use of header files.

A.     Structure of C Program and Example

B.      What is the use of header files in C language?

A header file is generally used to define all of the functions, variables and constants contained in any function library that you might want to use.

The header file stdio.h should be used for using the two standard I/O functions printf() and scanf().

The header file conio.h should be used for using console functions clrscr() and getch().

The header file ctype.h should be used for using character manipulation functions toupper(), tolower().

The header file string.h should be used for using string manipulation functions strlwr(), strlen(), strrev().

The header file math.h should be used for using math functions exp(), pow(), sqrt(), log().