# C Program to Calculate the Power of a Number

To understand this example, you should have knowledge of following C programming topics:

This program below takes two integers from user, a base number and an exponent. For example: In case of 2^{3}, 2 is the base number and 3 is the exponent of that number. And this program calculates the value of base^{exponent}.

## Source Code to Calculate Power

```
/* C program to calculate the power of an integer*/
#include <stdio.h>
int main()
{
int base, exp;
long long int value=1;
printf("Enter base number and exponent respectively: ");
scanf("%d%d", &base, &exp);
while (exp!=0)
{
value*=base; /* value = value*base; */
--exp;
}
printf("Answer = %d", value);
}
```

**Output**

Enter base number and exponent respectively: 3 4 Answer = 81

This program takes base number and exponent from user and stores in variable `base` and `exp` respectively. Let us suppose, user entered 3 and 4 respectively. Then, `while`

loop is executed with test condition `exp!=0`

. This test condition will be true and `value` becomes 3 after first iteration and value of exp will be decreased to 3. This process goes on and after fourth iteration, `value` will be equal to 81(3*3*3*3) and `exp` will be equal to 0 and `while`

loop will be terminated. Here, we have declared variable value of type `long long int`

because power of a number can be very large.

This program can only calculate the power if base power and exponent are integers. If you need to the calculate power of a floating point number then, you can use pow() function.