round3
Round to nearest integer, away from zero
Usage
#include <math.h>
double round(double x); float roundf(float x); long double roundl(long double x);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
round(), roundf(), roundl():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
Library
Math library (libm, -lm)
Overview
These functions round x to the nearest integer, but round halfway cases away from zero (regardless of the current rounding direction, see fenv(3)), instead of to the nearest even integer like rint(3).
For example, round(0.5) is 1.0, and round(-0.5) is -1.0.
Return value
These functions return the rounded integer value.
If x is integral, +0, -0, NaN, or infinite, x itself is returned.
Errors
No errors occur.
Attributes
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| round(), roundf(), roundl() | Thread safety | MT-Safe |
Releases
13 releases since Debian 3.0 (Woody); the text changed 12 times.