# C++ Program to Calculate Power of a Number

In this example, we will learn to compute power to a number manually, and by using pow() function.

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

## Power of a Number

This program takes two numbers from the user (a base number and an exponent) and calculates the power.

Power of a number = base^{exponent}

## Example 1: Program to Compute Power Manually

```
#include <iostream>
using namespace std;
int main()
{
int exponent;
float base, result = 1;
cout << "Enter base and exponent respectively: ";
cin >> base >> exponent;
cout << base << "^" << exponent << " = ";
while (exponent != 0) {
result *= base;
--exponent;
}
cout << result;
return 0;
}
```

**Output**

Enter base and exponent respectively: 3.4 5 3.4^5 = 454.354

##### Working

As we know, the power of a number is the number multiplied by itself repeatedly. For example,

**5 ^{3} = 5 x 5 x 5 = 125**

Here, 5 is the **base** and 3 is the **exponent**.

In this program, we have calculated the power of a number using a `while`

loop.

```
while (exponent != 0) {
result *= base;
--exponent;
}
```

Remember that we have already initialized `result` as `1`

during
the beginning of the program.

Let us see how this `while`

loop works if `base == 5`

and
`exponent == 3`

.

Iteration | result *= base | exponent | exponent != 0 | Execute Loop? |
---|---|---|---|---|

1st | `5` |
`3` |
`true` |
Yes |

2nd | `25` |
`2` |
`true` |
Yes |

3rd | `125` |
`1` |
`true` |
Yes |

4th | `625` |
`0` |
`false` |
No |

However, the above technique works only if the exponent is a positive integer.

If you need to find the power of a number with any real number as an exponent, you
can use `pow()`

function.

## Example 2: Program to Compute power using pow() Function

```
#include <iostream>
#include <cmath>
using namespace std;
int main()
{
float base, exponent, result;
cout << "Enter base and exponent respectively: ";
cin >> base >> exponent;
result = pow(base, exponent);
cout << base << "^" << exponent << " = " << result;
return 0;
}
```

**Output**

Enter base and exponent respectively: 2.3 4.5 2.3^4.5 = 42.44

##### Working

In this program, we have used the `pow()`

function to calculate the power
of a number.

Notice that we have included the `cmath`

header file in order to use the
`pow()`

function.

We take the `base` and `exponent` from the user.

We then use the `pow()`

function to calculate the power. The first
argument is the base, and the second argument is the exponent.

## Next Example

We hope that this Example helped you develop better understanding of the concept of "Find Power of a Number" in C++.

**Keep Learning : )**

In the next Example, we will learn about C++
`Program to Check a Number is Palindrome or Not`

.