floor, floorf, floorl

Calculates the floor of a value.

Syntax

``````double floor(
double x
);
float floor(
float x
); // C++ only
long double floor(
long double x
); // C++ only
float floorf(
float x
);
long double floorl(
long double x
);
``````

Parameters

x
Floating-point value.

Return Value

The floor functions return a floating-point value that represents the largest integer that is less than or equal to x. There is no error return.

Input SEH Exception Matherr Exception
± QNAN,IND none _DOMAIN

floor has an implementation that uses Streaming SIMD Extensions 2 (SSE2). For information and restrictions about using the SSE2 implementation, see _set_SSE2_enable.

Remarks

C++ allows overloading, so you can call overloads of floor that take and return float and long double values. In a C program, floor always takes and returns a double.

Requirements

floor, floorf, floorl <math.h>

For additional compatibility information, see Compatibility.

Example

``````// crt_floor.c
// This example displays the largest integers
// less than or equal to the floating-point values 2.8
// and -2.8. It then shows the smallest integers greater
// than or equal to 2.8 and -2.8.

#include <math.h>
#include <stdio.h>

int main( void )
{
double y;

y = floor( 2.8 );
printf( "The floor of 2.8 is %f\n", y );
y = floor( -2.8 );
printf( "The floor of -2.8 is %f\n", y );

y = ceil( 2.8 );
printf( "The ceil of 2.8 is %f\n", y );
y = ceil( -2.8 );
printf( "The ceil of -2.8 is %f\n", y );
}
``````
``````The floor of 2.8 is 2.000000
The floor of -2.8 is -3.000000
The ceil of 2.8 is 3.000000
The ceil of -2.8 is -2.000000
``````