ceil(), ceilf()
Round up a value to the next integer
Synopsis:
#include <math.h> double ceil( double x ); float ceilf( float x );
Arguments:
- x
- The value you want to round.
Description:
The ceil() and ceilf() functions round the value of x up to the next integer (rounding towards the ceiling).
Returns:
The smallest integer ≥ x.
If an error occurs, these functions return 0, but this is also a valid
mathematical result.
If you want to check for errors, set
errno
to 0, call the function, and then check errno again.
These functions don't change errno if no errors occurred.
Examples:
#include <stdio.h>
#include <math.h>
#include <stdlib.h>
int main( void )
{
printf( "%f %f %f %f %f\n", ceil( -2.1 ),
ceil( -2. ), ceil( 0.0 ), ceil( 2. ),
ceil( 2.1 ) );
return EXIT_SUCCESS;
}
produces the output:
-2.000000 -2.000000 0.000000 2.000000 3.000000
Classification:
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | No |
| Thread | Yes |