C++之无符号整型减法

源代码

/**
  ******************************************************************************
  * @file    uint.cpp
  * @author  zhy
  * @version 1.0
  * @date    2021-03-05
  * @brief   无符号整形减法验证
  ******************************************************************************
  */

#include <iostream>

int main()
{
    unsigned short short1 = 1;
    unsigned short short2 = 0xFFFF;
    std::cout << "(unsigned short)(short1 - short2) = " << (unsigned short)(short1 - short2) << std::endl;
    std::cout << "short1 - short2 = " << short1 - short2 << std::endl;

    unsigned int int1 = 1;
    unsigned int int2 = 0xFFFFFFFF;
    std::cout << "(unsigned int)(int1 - int2) = " << (unsigned int)(int1 - int2) << std::endl;
    std::cout << "int1 - int2 = " << int1 - int2 << std::endl;
    return 0;
}

结果

(unsigned short)(short1 - short2) = 2
short1 - short2 = -65534
(unsigned int)(int1 - int2) = 2
int1 - int2 = 2

分析

在C++中，无符号的short和int的减法结果并不相同！