std::ceil

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Defined in header <cmath>

float       ceil( float arg );

double      ceil( double arg );

long double ceil( long double arg );

Computes nearest integer not less than arg.

Contents

[edit] Parameters

arg - floating point value

[edit] Return value

nearest integer not less than arg

[edit] Notes

The integer value can be always represented by the given floating point type.

[edit] Example

#include <cmath>
#include <iostream>
 
int main()
{
    double a = 12.0;
    std::cout << std::fixed;
    std::cout << std::ceil(12.0) << '\n';
    std::cout << std::ceil(12.1) << '\n';
    std::cout << std::ceil(12.5) << '\n';
    std::cout << std::ceil(12.9) << '\n';
    std::cout << std::ceil(13.0) << '\n';}

Output:

12.000000
13.000000
13.000000
13.000000
13.000000

[edit] See also

floor
nearest integer not greater than the given value
(function)
trunc (C++11)
nearest integer not greater in magnitude than the given value
(function)
round
lround
llround
(C++11)
(C++11)
(C++11)
nearest integer, rounding away from zero in halfway cases
(function)