c++17(25)-union

#include <iostream>#include <string.h>using namespace std;union Nums{int x;double y;char z;};int main(int argc, char **argv){Nums a;a.y=1.9238;cout<<a.y<<endl;a.x=18;cout<&l

AI_LX

257人浏览 · 2021-02-06 15:40:46

AI_LX · 2021-02-06 15:40:46 发布

#include <iostream>
#include <string.h>
using namespace std;

union Nums{
     int x;
     double y;
     char z;
};

int main(int argc, char **argv)
{
    Nums a;
    a.y=1.9238;
    cout<<a.y<<endl;
    a.x=18;
    cout<<a.x<<endl;
    a.z='a';
    cout<<a.z<<endl;
	return 0;
}

所有union地址一样，共享一个内存空间，空间大小为union成员中最大占用空间

#include <iostream>
#include <string.h>
using namespace std;

union Nums{
     int x;
     double y;
     char z;
};

int main(int argc, char **argv)
{
    Nums a;
    a.y=1.9238;
    cout<<a.y<<endl;
    a.x=18;
    cout<<a.x<<endl;
    a.z='a';
    cout<<a.z<<endl;
	return 0;
}