# C++ Program - Power of a Number

If power (or exponential) of number indicates how many the number is multiplied by itself to get the final number. For example:

x raised to the power 2 = x² = x*x

x raised to the power 3 = x³ = x*x*x

### Method 1: Using conditional statement

In the example below, a function called Power() is created to calculate power of a number. It uses while loop to achieve this. This method can be used to calculate the power of a number where power should be a non-negative integer.

```#include <iostream>
using namespace std;

static void Power(double, int);

static void Power(double x, int n) {
double finalnum = 1;
int n1 = n;
while(n1 > 0){
finalnum = finalnum * x;
n1--;
}
cout<<x<<" raised to the power "<<n<<" = "<<finalnum<<"\n";
}

int main() {
Power(3, 5);
Power(5, 0);
Power(6, 2);
return 0;
}
```

The above code will give the following output:

```3.0 raised to the power 5 = 243.0
5.0 raised to the power 0 = 1.0
6.0 raised to the power 2 = 36.0
```

### Method 2: Using pow() function of C++ <cmath> header file

The pow() function of C++ <cmath> header file can also be used to calculate power of a number. It can be used to calculate xn for any value of n (n can be negative or fraction).

```#include <iostream>
#include <cmath>
using namespace std;

int main() {
double x = 3, y = 5, z = 6;
double a = 5, b = 0, c = 2;

cout<<x<<" raised to the power "<<a<<" = "<<pow(x, a)<<"\n";
cout<<y<<" raised to the power "<<b<<" = "<<pow(y, b)<<"\n";
cout<<z<<" raised to the power "<<c<<" = "<<pow(z, c)<<"\n";
return 0;
}
```

The above code will give the following output:

```3.0 raised to the power 5.0 = 243.0
5.0 raised to the power 0.0 = 1.0
6.0 raised to the power 2.0 = 36.0
```

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