What is operator?

Operator-
An operator is symbol which       
used to operate variables and data.
Operator symbols helps to the users for applying the commonds to complete mathematical manipulations.
C has many operators--
1 Arithmatic operator
2 Relational operator
3 Logic operator
4 Assignment operator
5 Increment &decrement operator
6 Bitwise operator

1.Arithmetic operator-:
       
In this operator mostly mathematical symbols like plus, minus etc.
Ex.
   Operator                       work of operator
       +                              For addition
        -                              For subtraction
        *                              For multiplication
         /                             For division
        %                (modulo) for find reminder

2.Relational operator-:

These types of operator shows the relationship among to the functions.

Operator                        work of operator
      <                                is less than
      <=                       is less than or equal to
      >                                is greater than
      >=                  is greater than or equal to
      ==                              is equal to
      !=                                is not equal to

3.Logic operator-:

Operator                        work of operator
   &&                                     logic AND
     ||                                      logic OR
     !                                        logic NOT

4. Assignment operator-:

Operator                        work of operator
    =                                   for assign a value
    *=                              multiply and assign
    /=                             divide and assign
   %=                              moduls and assign
    +=                              add and assign
     -=                              substrct and assign
5.Increment and Decrement operator-:

Operator                        work of operator
   ++                                   increment
    --                                    decrement

6.Bitwise operator-:

Operator                        work of operator

    &                                     AND
     |                                     Inclusive OR
     ^                                    Exclusive OR
    <<                                    Shift left
    >>                                    Shift right
     ~                                 One's compliment

How to write a program to add two numbers?

#include<stdio.h>
#include<conio.h>
void main()
{
  int a, b, sum;
  clrscr();
   printf("Enter your two numbers =");
  scanf("%d%d",&a,&b);
   sum=a+b;
   printf ("The sum of numbers=%d",sum);
  getch();
}
Output is--
Enter your two numbers=5
                                            9
sum of two numbers=14