C++ <cmath> - ldexp() Function

The C++ <cmath> ldexp() function returns the result of multiplying the significand (x) by 2 raised to the power of the exponent (exp), i.e., x * 2^exp.

Syntax

C++98
C++11

double ldexp (double x, int exp);
float ldexp (float x, int exp);
long double ldexp (long double x, int exp);

double ldexp (double x, int exp);
float ldexp (float x, int exp);
long double ldexp (long double x, int exp);
//additional overloads for integral types
double ldexp (T x, int exp);

Parameters

`x`	Specify floating point value representing the significand.
`exp`	Specify value of the exponent.

Return Value

Returns x * 2^exp.

Example:

The example below shows the usage of ldexp() function.

#include <iostream>
#include <cmath>
using namespace std;
 
int main (){
  double x, result;
  int exp;
  x = 0.9;
  exp = 4;

  result = ldexp(x, exp);

  cout<<"Significand: "<<x<<"\n";
  cout<<"Exponent: "<<exp<<"\n";
  cout<<"Result: "<<result<<"\n";
  return 0;
}

The output of the above code will be:

Significand: 0.9
Exponent: 4
Result: 14.4

❮ C++ <cmath> Library