6.11.29 ceil Function

Calculates the ceiling of a value.

Include

<math.h>

Prototype

double ceil(double x);

Argument

x

a floating-point value for which to return the ceiling

Return Value

Returns the smallest integer value greater than or equal to x.

Remarks

No domain or range error will occur. See floor.

Example

See the notes at the beginning of this chapter or section for information on using printf() or scanf() (and other functions reading and writing the stdin or stdout streams) in the example code.

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

int main(void)
{
  double x[8] = {2.0, 1.75, 1.5, 1.25, -2.0, -1.75, -1.5, -1.25};
  double y;
  int i;

  for (i=0; i<8; i++)
  {
    y = ceil (x[i]);
    printf("The ceiling for  %f is  %f\n", x[i], y);
  }
}

Example Output

The ceiling for  2.000000 is  2.000000
The ceiling for  1.750000 is  2.000000
The ceiling for  1.500000 is  2.000000
The ceiling for  1.250000 is  2.000000
The ceiling for  -2.000000 is  -2.000000
The ceiling for  -1.750000 is  -1.000000
The ceiling for  -1.500000 is  -1.000000
The ceiling for  -1.250000 is  -1.000000