ceil
round to smallest integral value not less than x
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INTERFACE
#include <math.h>
double ceil ( double x ) long ceill ( long double x ) float ceilf ( float x )
DESCRIPTION
The ceil function returns the smallest integral value greater than or equal to x.
Example 1
#include <stdio.h>
#include <math.h>
int main(void)
{
for(double a = 12; a < 13; a += 0.1)
printf("ceil of %.1lf is %.1lf\n", a, ceil(a));
return 0;
}Output
ceil of 12.0 is 12.0
ceil of 12.1 is 13.0
ceil of 12.2 is 13.0
ceil of 12.3 is 13.0
ceil of 12.4 is 13.0
ceil of 12.5 is 13.0
ceil of 12.6 is 13.0
ceil of 12.7 is 13.0
ceil of 12.8 is 13.0
ceil of 12.9 is 13.0
ceil of 13.0 is 13.0SPECIAL VALUES
ceil ( ±0 ) returns ±0.
ceil ( ±&infin ) returns ±∞.
SEE ALSO
STANDARDS
The ceil function conform to ISO/IEC 9899:1999(E).