Calculate the Power of a Number in C++

base^exponent in C++ with pow. 2^8 is 256. ^ is XOR, not power.

BeginnerLoop ProgramsExample 12 of 14

calculate-the-power-of-a-number.cpp

1#include <iostream>
2#include <cmath>
3using namespace std;
4
5int main() {
6    double base, exponent, result;
7    
8    cout << "Enter base: ";
9    cin >> base;
10    
11    cout << "Enter exponent: ";
12    cin >> exponent;
13    
14    result = pow(base, exponent);
15    
16    cout << base << " raised to the power " << exponent << " = " << result << endl;
17    
18    return 0;
19}

Output

Enter base: 2
Enter exponent: 8
2 raised to the power 8 = 256

What's going on

This C++ program computes base^exponent with pow from <cmath>. 2^8 is 256.

#include <cmath>

Skip it and pow is an unknown name.

double base, exponent, result;

double so 2.5 and -2 still work. int would truncate 2^(-3).

result = pow(base, exponent);

^ is XOR. 2 ^ 8 is 10, not 256. Don't.

Special cases pow already handles: anything^0 is 1, 2^1 is 2. Fractional exponent 4^0.5 is 2. Negative exponent 2^-3 is 0.125.

A loop result *= base n times only works for a non-negative integer exponent. That's why the library function exists.

Sample: 2 raised to the power 8 = 256.

Previousnth Fibonacci Number NextFactors of a Natural Number