# floor(), floorf(), floorl()

Round down a value to the next integer

## Synopsis:

```#include <math.h>

double floor( double x );

float floorf( float x );

long double floorl(long double x);
```

## Arguments:

x
The value you want to round.

## Library:

libm

Use the -l m option to qcc to link against this library.

## Description:

The floor(), floorf(), and floorl() functions compute the largest integer less than or equal to x (rounding towards the “floor”).

To check for error situations, use feclearexcept() and fetestexcept(). For example:

• Call feclearexcept(FE_ALL_EXCEPT) before calling floor(), floorf(), or floorl().
• On return, if fetestexcept(FE_ALL_EXCEPT) is nonzero, then an error has occurred.

## Returns:

The largest integer less than or equal to x.

If x is: These functions return: Errors:
±0.0 x
±Inf x
NaN NaN

These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.

## Examples:

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

int main( void )
{
printf( "%f\n", floor( -3.14 ) );
printf( "%f\n", floor( -3. ) );
printf( "%f\n", floor( 0. ) );
printf( "%f\n", floor( 3.14 ) );
printf( "%f\n", floor( 3. ) );

return EXIT_SUCCESS;
}
```

produces the output:

```-4.000000
-3.000000
0.000000
3.000000
3.000000
```

## Classification:

Safety:
Cancellation point No
Interrupt handler No
Signal handler No