Updated: April 19, 2023 |
Round down a value to the next integer
#include <math.h> double floor( double x ); float floorf( float x ); long double floorl(long double x);
Your system requirements will determine how you should work with these libraries:
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:
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.
#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
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | Yes |
Signal handler | Yes |
Thread | Yes |