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std::abs(int), std::labs, std::llabs, std::imaxabs

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Common mathematical functions
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abs(int)labsllabsimaxabs
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Defined in header <cstdlib>
int       abs( int n );
long      abs( long n );
long long abs( long long n );
(since C++11)
long       labs( long n );
long long llabs( long long n );
(since C++11)
Defined in header <cinttypes>
(since C++11)
(since C++11)

Computes the absolute value of an integer number. The behavior is undefined if the result cannot be represented by the return type.

Contents

[edit] Parameters

n - integer value

[edit] Return value

The absolute value of n (i.e. |n|), if it is representable.

[edit] Notes

In 2's complement systems, the absolute value of the most-negative value is out of range, e.g. for 32-bit 2's complement type int, INT_MIN is -2147483648, but the would-be result 2147483648 is greater than INT_MAX, which is 2147483647.

[edit] Example

#include <iostream>
#include <cstdlib>
#include <climits>
 
int main()
{
    std::cout << "abs(+3) = " << std::abs(3) << '\n'
              << "abs(-3) = " << std::abs(-3) << '\n';
 
//  std::cout << abs(INT_MIN)); // undefined behavior on 2's complement systems
}

Output:

abs(+3) = 3
abs(-3) = 3

[edit] See also

absolute value of a floating point value (|x|)
(function) [edit]
returns the magnitude of a complex number
(function template) [edit]
applies the function std::abs to each element of valarray
(function template) [edit]
C documentation for abs, labs, llabs