Updated: April 19, 2023 |
Round a floating-point number to the nearest integer value
#include <math.h> long int lround( double x ); long int lroundf( float x ); long int lroundl( long double x );
Your system requirements will determine how you should work with these libraries:
The lround(), lroundf(), and lroundl() functions round a floating-point number to the nearest integer value, rounding halfway cases away from zero, regardless of the current rounding direction.
To check for error situations, use feclearexcept() and fetestexcept(). For example:
The rounded integer value.
If: | These functions return: | Errors: |
---|---|---|
x is ±Inf | An unspecified value | FE_INVALID |
x is NaN | An unspecified value | FE_INVALID |
The correct value is too large to represent as a long | An unspecified value | FE_INVALID |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | Yes |
Signal handler | Yes |
Thread | Yes |