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std::ceil

From cppreference.com
< cpp‎ | numeric‎ | math
 
 
 
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Defined in header <cmath>
float       ceil( float arg );
double      ceil( double arg );
long double ceil( long double arg );
double      ceil( Integral arg );
(since C++11)

Computes nearest integer not less than arg.

Contents

[edit] Parameters

arg - floating point value

[edit] Return value

Nearest integer not less than arg

Return value
math-ceil.svg
Argument

[edit] Notes

If the argument is infinity (positive or negative) or zero (positive or negative), the return value is the same as the argument.

The largest representable floating-point values are exact integers in all standard floating-point formats, so this function never overflows.

This function may, but is not required to, raise FE_INEXACT floating-point exceptions for non-integer arguments.

[edit] Example

#include <cmath>
#include <iostream>
 
int main()
{
    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

nearest integer not greater than the given value
(function) [edit]
(C++11)
nearest integer not greater in magnitude than the given value
(function) [edit]
(C++11)(C++11)(C++11)
nearest integer, rounding away from zero in halfway cases
(function) [edit]
(C++11)(C++11)(C++11)
nearest integer using current rounding mode with
exception if the result differs
(function) [edit]
(C++11)
nearest integer using current rounding mode
(function) [edit]