Rounds a real number up to an integer value

#include <math.h>
double ceil ( double x  );
float ceilf ( float x  );         (C99)
long double ceill ( long double x  );         (C99)

The ceil( ) function returns the smallest integer that is greater than or equal to its argument. However, the function does not have an integer type; it returns an integer value, but with a floating-point type.

Example

/* Amount due = unit price * count * VAT, rounded up to the next cent */
div_t total = { 0, 0 };
int count = 17;
int price = 9999;           // 9999 cents is $99.99
double vat_rate = 0.055;    // Value-added tax of 5.5%

total = div( (int)ceil( (count * price) * (1 + vat_rate)), 100);

printf("Total due: $%d.%2d\n", total.quot, total.rem);

This code produces the following output:

Total due: $1793.33

See Also

floor( ), floorf( ), and floorl( ), round( ), roundf( ), and roundl( ); the C99 rounding functions that return floating-point types: trunc( ), rint( ), nearbyint( ), nextafter( ), nexttoward( ); the C99 rounding functions that return integer types: lrint( ), lround( ), llrint( ), llround( ); the fesetround( ) and fegetround( ) functions, which operate on the C99 floating-point environment.