C++ pow()

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

int main() {

  // computes 5 raised to the power 3
  cout << pow(5, 3);

  return 0;
}

// Output: 125

pow() Syntax

The syntax of the pow() function is:

pow(double base, double exponent);

pow() Parameters

The pow() function takes two parameters:

• base - the base value
• exponent - exponent of the base

pow() Return Value

The pow() function returns:

• the result of baseexponent
• 1.0 if exponent is zero
• 0.0 if base is zero

pow() Prototypes

The prototypes of pow() as defined in the cmath header file are:

double pow(double base, double exponent);

float pow(float base, float exponent);

long double pow(long double base, long double exponent);

// for other argument types
Promoted pow(Type1 base, Type2 exponent);

Since C++ 11,

• if any argument passed to pow() is long double, the return type Promoted is long double
• else, the return type Promoted is double

Example 1: C++ pow()

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

int main () {
  double base, exponent, result;
	
  base = 3.4;
  exponent = 4.4;

  result = pow(base, exponent);
	
  cout << base << " ^ " << exponent << " = " << result;
	
  return 0;
}

Output

3.4 ^ 4.4 = 218.025

Example 2: pow() With Different Arguments

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

int main () {
  long double base = 4.4, result;
  int exponent = -3;

  result = pow(base, exponent);

  cout << base << " ^ " << exponent << " = " << result << endl;
	
  // initialize int arguments
  int int_base = -4, int_exponent = 6;

  double answer;

  // pow() returns double in this case
  answer = pow(int_base, int_exponent);

  cout << int_base << " ^ " << int_exponent << " = " << answer;
	
  return 0;
}

Output

4.4 ^ -3 = 0.0117393
-4 ^ 6 = 4096