The function **double ceil(double x);** returning the smallest integral value greater than or equal to x.

## Function prototype of ceil

*double ceil(double x);***x**: A floating point value to round up.

## Return value of ceil

Function ceil returns the smallest integral value greater than or equal to x(as a floating-point value).

## C program using ceil function

The following program shows the use of ceil function to round up value of floating point number.

#include <stdio.h> #include <math.h> int main () { double x, result; printf("Enter a number\n"); scanf("%lf", &x); result = ceil(x); printf("Smallest integer >= of %lf is %lf\n", x, result); return 0; }

Output

Enter a number 2.3 Smallest integer >= of 2.300000 is 3.000000

Enter a number -2.3 Smallest integer >= of -2.300000 is -2.000000