idexp C Library Function

The function double ldexp(double x, int exponent); returns the result of multiplying x with 2 raised to the power of exponent( x * 2^exponent).

Function prototype of idexp

double ldexp(double x, int exponent);

• x : A floating point value representing the mantisa.
• exponent : An integer representing the value of exponent of 2.

Return value of idexp

It returns the value of x * 2^exponent.

C program using idexp function

The following program shows the use of idexp function.

#include <stdio.h>
#include <math.h>
 
int main ()
{
  double x, result;
  int exponent;
 
  printf("Enter a number and exponent\n");
  scanf("%lf %d", &x, &exponent);
   
  /* It returns x*(2^exponent)  */
  result = ldexp(x, exponent);
  printf("%lf * 2^%d = %lf\n", x, exponent, result);
   
  return 0;
}

Output

Enter a number and exponent
3.5 4
3.500000 * 2^4 = 56.000000