What is nextafterl() in C?

The nextafterl() function produces the smallest possible value after a number in a given direction. The declaration of nextafterl() is shown below:

long double nextafterl (long double num, long double dir);

Parameters

  • num: The base number
  • dir: The direction of the floating point with respect to num.

Return value

The nextafterl() function returns the next representable floating-point number after num in the direction of dir.

Library

To use the nextafterl() function, include the following library:

#include <math.h>

Example

Consider the code snippet below, which demonstrates the implementation of nextafterl():

#include <stdio.h>
#include <math.h>
int main() {
  double a = 0.0;
  double b = 1.0;
  double x = nextafter(a, b);
  printf("nextafterl ( %f, %f ) = ( %e ) \n", a, b, x);
  
  return 0;
}

Explanation

The nextafterl() function is used in line 9 to compute the next representable floating-point number after a in the direction of b.

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