floor, floorf, floorl
Header: <math.h>
1-3) Computes the largest integer value not greater than arg.
# Declarations
float floorf( float arg );
(since C99)
double floor( double arg );
long double floorl( long double arg );
(since C99)
#define floor( arg )
(since C99)
# Parameters
arg: floating-point value
# Return value
If no errors occur, the largest integer value not greater than arg, that is ⌊arg⌋, is returned.
# Notes
FE_INEXACT may be (but isn’t required to be) raised when rounding a non-integer finite value.
The largest representable floating-point values are exact integers in all standard floating-point formats, so this function never overflows on its own; however the result may overflow any integer type (including intmax_t), when stored in an integer variable.
# Example
#include <math.h>
#include <stdio.h>
int main(void)
{
printf("floor(+2.7) = %+.1f\n", floor(2.7));
printf("floor(-2.7) = %+.1f\n", floor(-2.7));
printf("floor(-0.0) = %+.1f\n", floor(-0.0));
printf("floor(-Inf) = %+f\n", floor(-INFINITY));
}