# C++ program to find the power of a number

# Introduction :

In this tutorial, we will learn how to find the power of a number in C++. We can use one loop to find the power or C++ provides one method called *pow()* to find the power.

The program will ask the user to enter two numbers: the *base number* and the *exponent*. It will calculate and print out the power using the *base* and *exponent*.

## Calculate power using a loop :

We can use any loop to solve it. In the program below, I am using one *while* loop :

#include <iostream> using namespace std; int main() { //1 float b, e, result = 1; //2 cout << "Enter base : "; cin >> b; cout << "Enter exponent : "; cin >> e; //3 while (e != 0) { result *= b; e--; } //4 cout << "Result : " << result << endl; }

### Explanation :

*The commented numbers in the above program denote the step numbers below :*

- Create three floating-point numbers to store the user-provided values and the result values.
- Ask the user to enter the
*base*value. Read and store it in variable*b*. Similarly, read and store the*exponent*value in variable*e*. - Run one
*while loop*to find out the final power i.e.*b*to the power*e*. For that, we need to multiply*b*to its own value*e*times. The*while loop*makes sure that the multiplication is done properly. It decrements the value of*e*on each iteration of the loop and stops the loop once the value of*e*reaches*0*. Inside the loop, we are multiplying the value of*b*to*result*i.e. once the loop will end,*result*will hold the final*power*. - Finally, print out the result to the user.

### Sample output :

Enter base : 4 Enter exponent : 3 Result : 64

Similarly, we can use one *for loop* or *do while* loop to find out the power of a number.

## Calculate power using pow() :

C++ header *cmath* includes one function called *pow()* to calculate the power of a number easily without writing any extra code. It is defined as below :

double pow(double base,double exponent)

It takes two *double* parameters i.e. *base*, *exponent* and returns the power in *double* format.

#include <iostream> #include <cmath> using namespace std; int main() { float b, e, result = 1; cout << "Enter base : "; cin >> b; cout << "Enter exponent : "; cin >> e; result = pow(b,e); cout << "Result : " << result << endl; }

The only thing you need to remember is that *cmath* is required to use *pow()*.

### Conclusion :

In this tutorial, we have learned how to find the power of a number in C++ using two different approaches. You can write your own function to calculate the power or you can directly use the *cmath* header file for that. Try to go through the examples above and drop one comment below if you have any queries.

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