In this C++ tutorial, you will learn how to compute the value of x scaled by FLT_RADIX to the power exp using scalbln() function of cmath, with syntax and examples.
C++ scalbln()
C++ scalbln(x, exp) computes the value of x scaled by FLT_RADIX to the power exp.
scalbln(x, exp) = x * FLT_RADIX^exp
Syntax
The syntax of C++ scalbln() is
scalbln(x, exp)
where
| Parameter | Description |
|---|---|
| x | A double, float, long double, or integral type value. |
| exp | A long int value. |
Returns
The return value depends on the type of value passed for parameter x.
The return value of scalbln(x, exp) is
- double if x is double or integral type value.
- float if x is float.
- long double if x is long double.
The synopsis of scalbln() function is
double scalbln(double x, long int exp); float scalbln(float x, long int exp); long double scalbln(long double x, long int exp); double scalbln(Type1 x, long int exp); // for integral types
scalbln() is a function of cmath library. Include cmath library at the start of program, if using scalbln() function.
Example
In this example, we read two values from user into variables x and exp, and compute result of scalbln(x, exp).
C++ Program
#include <iostream>
#include<cmath>
using namespace std;
int main() {
double x;
long int exp;
cout << "Enter x : ";
cin >> x;
cout << "Enter exp : ";
cin >> exp;
double result = scalbln(x, exp);
cout << "scalbln(" << x << ") : " << result << endl;
} Output
Enter x : 5 Enter exp : 3 scalbln(5) : 40 Program ended with exit code: 0
Enter x : 8 Enter exp : 1 scalbln(8) : 16 Program ended with exit code: 0
If x is NaN, scalbn() returns NaN.
Enter x : nan Enter exp : 3 scalbln(nan) : nan Program ended with exit code: 0
Conclusion
In this C++ Tutorial, we learned the syntax of C++ scalbln(), and how to use this function, with the help of examples.