c99 [ flag... ] file... -lm [ library... ] #include <math.h>
double round(double x);
float roundf(float x);
long double roundl(long double x);
These functions round their argument to the nearest integer value in floating-point format, rounding halfway cases away from 0, regardless of the current rounding direction.
Upon successful completion, these functions return the rounded integer value.
If x is NaN, a NaN is returned.
If x is ±0 or ± Inf, x is returned.
See attributes(5) for descriptions of the following attributes:
ATTRIBUTE TYPE | ATTRIBUTE VALUE |
Interface Stability | Standard |
MT-Level | MT-Safe |
feclearexcept(3M), fetestexcept(3M), math.h(3HEAD), attributes(5), standards(5)