std::abs, std::labs, std::llabs, std::imaxabs

int       abs( int n );

long      abs( long n );

long long abs( long long n );

long       labs( long n );

long long llabs( long long n );

std::intmax_t abs( std::intmax_t n );

std::intmax_t imaxabs( std::intmax_t n );

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

Parameters

Return value

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

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.

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 << std::abs(INT_MIN); // undefined behavior on 2's complement systems
}

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

See also