# C Program to Calculate Power of a Number

The power of a number can be defined as how many times the number is multiplied with itself. For example:

9^{3}= 9 X 9 X 9 = 729 2^{5}= 2 X 2 X 2 X 2 X 2 = 32

This can be written in the form x^{n}. So, in this program we ask the user to input the value of *x* and *n*.

## Example 1: Calculating Power Using Loop

#include<stdio.h> int main() { int i=1, x, n, ans=1; printf("Enter x and power n \n"); scanf("%d \n %d", &x, &n); while (i<=n) { ans = ans*x; i = i+1; } printf("%d to the power %d is %d", x, n, ans); return 0; }

Here, the user is asked to enter value of *x* and *n*. Variable *i* is initialized to 1 as it acts as counter for the loop. And the loop is to be executed as long as *i<=n* as the number has to be multiplied with itself for *n* times. Variable *ans* is initialized to 1 at first as* ans* is stored in this variable. In the first loop,

*ans = ans * x;*

If the user has input value of x as 2 and n as 4 then,

*ans = 1 * 2* i.e. ans =2

On the second loop,

*ans = ans * x *i.e. ans = 2 * 2 = 4

On the third loop,

*ans = ans * x *i.e. ans = 4 * 2 = 8

And, on the fourth loop,

*ans = ans * x *i.e. ans = 8 * 2 = 16 which is the final answer.

## Example 2: Calculating Power Using *pow()* Function

In C program, there is a function pow(), defined in the header file <math.h> which calculates the power of a number.

#include<stdio.h> #include<math.h> int main() { int i=1, x, n, ans=1; printf("Enter x and power n \n"); scanf("%d \n %d",&x, &n); ans= pow (x,n); printf("%d to the power %d is %d", x, n, ans); return 0; }

**Output:**

Enter x and power n 3 4 3 to the power 4 is 81