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  C++ Library Reference : C Library : cmath (math.h) : ceil
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functions:
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· ceil
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· HUGE_VAL

-

ceil function
     double ceil (      double x );
      float ceil (       float x );
long double ceil ( long double x );
<cmath>

Round up value

Returns the smallest integral value that is not less than x.

Parameters

x
Floating point value.

Return Value

The smallest integral value not less than x.

Portability

In C, only the double version of this function exists with this name.

Example

/* ceil example */
#include <stdio.h>
#include <math.h>

int main ()
{
  printf ("ceil of 2.3 is %.1lf\n", ceil (2.3) );
  printf ("ceil of 3.8 is %.1lf\n", ceil (3.8) );
  printf ("ceil of -2.3 is %.1lf\n", ceil (-2.3) );
  printf ("ceil of -3.8 is %.1lf\n", ceil (-3.8) );
  return 0;
}

Output:


ceil of 2.3 is 3.0
ceil of 3.8 is 4.0
ceil of -2.3 is -2.0
ceil of -3.8 is -3.0

See also

floor Round down value (function)
fabs Compute absolute value (function)
modf Break into fractional and integral parts (function)
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