### C++

function
<cmath> <ctgmath>

# ceil

`double ceil (double x);`
`     double ceil  (double x);      float ceilf (float x);long double ceill (long double x);`
`     double ceil (double x);      float ceil (float x);long double ceil (long double x);`
`     double ceil (double x);      float ceil (float x);long double ceil (long double x);     double ceil (T x);           // additional overloads for integral types`
Round up value
Rounds x upward, returning the smallest integral value that is not less than x.

Header <tgmath.h> provides a type-generic macro version of this function.
Additional overloads are provided in this header (`<cmath>`) for the integral types: These overloads effectively cast x to a `double` before calculations (defined for T being any integral type).

### Parameters

x
Value to round up.

### Return Value

The smallest integral value that is not less than x (as a floating-point value).

### Example

 ``123456789101112`` ``````/* ceil example */ #include /* printf */ #include /* ceil */ int main () { printf ( "ceil of 2.3 is %.1f\n", ceil(2.3) ); printf ( "ceil of 3.8 is %.1f\n", ceil(3.8) ); printf ( "ceil of -2.3 is %.1f\n", ceil(-2.3) ); printf ( "ceil of -3.8 is %.1f\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 ```