C++ Usage and examples of scalbln() function

C++ Library Function <cmath>

C ++The scalbln(x, n) function in the scalbln() takes two parameters: x and n, and raises x to the nth power of the FLT_RADIX base.

In short, simply put, the scalbln() function returns the product of x and the nth power of the FLT_RADIX base.

FLT_RADIX is the value of the base (integer base) in exponential notation.

The function is in<cmath>Defined in the header file. In addition, you need to use the <cfloat> header file to use FLT_RADIX.

scalbln(x, n) = x　*　FLT_RADIXn

scalbln() prototype [from C ++ 11Standard library begins]

double scalbln(double x, long int n);
float scalbln(float x, long int n);
long double scalbln(long double x, long int n);
double scalbln(T x, long int n);　//Here, T is an integer type

It is similar toscalbn() functionare the same, but it uses long int as the second parameter.

scalbln() parameters

scalbln() has two parameters:

• x -The value representing the number of significant digits

• n-The exponent value of FLT_RADIX

The return value of scalbln()

The return value of scalbln() is x * FLT_RADIXⁿ

If the result is too large to be represented by the return type's value, the function will return HUGE_VAL with the correct sign.

Example: How does scalbln() work?

#include <iostream>
#include <cmath>
#include <cfloat>
using namespace std;
int main()}
{
　　　　long int n =　133;
　　　　double x =　3.056, result;
　　　　result = scalbln(x, n);
　　　　cout << x << "　*　cout << x << " << FLT_RADIX << "^" << n << " = " << result << endl;
　　　　
　　　　return 0;
}

The output when running the program is:

3.056　*　2^133　=　3.32769e+40

C++ Library Function <cmath>