In this C++ tutorial, you will learn how to find the next representable value after x in direction of y, using nextafter() function of cmath, with syntax and examples.
C nextafter
C++ nextafter(x, y) next representable value after x in direction of y.
Syntax
The syntax of C++ nextafter() is
nextafter(x, y)
where
| Parameter | Description |
|---|---|
| x | A double, float, long double, or integral type value. |
| y | A double, float, long double, or integral type value. |
Returns
The return value depends on the type of value passed for parameter x.
The return value of nextafter() is
- double if x is double or integral type.
- float if x is float.
- long double if x is long double.
The synopsis of nextafter() function is
double nextafter(double x, double y); float nextafter(float x, float y); long double nextafter(long double x, long double y); Promoted nextafter(Type1 x, Type2 y); // where Type1 and Type2 are any integral type values
nextafter() is a function of cmath library. Include cmath library at the start of program, if using nextafter() function.
Example
In this example, we read two values from user, into variables x and y, and compute the next representable value next to x towards y using nextafter() function.
C++ Program
#include <iostream>
#include<cmath>
using namespace std;
int main() {
long double x, y;
cout << "Enter x : ";
cin >> x;
cout << "Enter y : ";
cin >> y;
long double result = nextafter(x, y);
cout << "Next Value : " << result << endl;
}
Output
Enter x : inf Enter y : 0 Next Value : 1.79769e+308 Program ended with exit code: 0
Enter x : -inf Enter y : 0 Next Value : -1.79769e+308 Program ended with exit code: 0
Enter x : 8555246635 Enter y : 0 Next Value : 8.55525e+09 Program ended with exit code: 0
Conclusion
In this C++ Tutorial, we learned the syntax of C++ nextafter(), and how to use this function to find the next representable value of a number in the direction of other number, with the help of examples.