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std::labs

STD：：ABS%28int%29，STD：：Labs，STD：：llab，STD：：imaxabs

Defined in header ​​
Defined in header <cmath>​(since C++17)
int abs( int n ​​
long abs( long n ​​
long long abs( long long n ​(since C++11)
Defined in header <cstdlib>​​
long labs( long n ​​
long long llabs( long long n ​(since C++11)
Defined in header <cinttypes>​​
std::intmax_t abs( std::intmax_t n ​(since C++11)
std::intmax_t imaxabs( std::intmax_t n ​(since C++11)

计算整数的绝对值。如果返回类型不能表示结果，则行为未定义。

参数

n-integer value

返回值

绝对值n%28i.e.|n|%29，如果它是可代表的。

注记

在2%27 s补码系统中，最大负值的绝对值超出了范围，例如32位2%27 s补码类型int，int。[医]最小值为-2147483648，但预期结果2147483648大于int。[医]最高值是2147483647。

例

二次

#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
}

二次

产出：

二次

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

二次

另见

abs(float) fabsabsolute value of a floating point value (|x|) (function)
abs(std::complex)returns the magnitude of a complex number (function template)
abs(std::valarray)applies the function std::abs to each element of valarray (function template)

为abs，实验室，llab编写文档

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在CreativeCommonsAttribution下授权-ShareAlike未移植许可v3.0。

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