7-1.cpp

为初学者提供的最佳的C++程序设计源程序库

#include<iostream.h>
void main()
{
   int size;
   union u_tag
	  {
	   int i;
	   double d;
	  }u={88};
   struct s_tag
	   {
	    int i;
		double d;
	   }s={66,1.234};
	size=sizeof(union u_tag);
    cout<<"sizeof(union u_tag)="<<size<<endl;
    u.i=100;
	cout<<"u.i="<<u.i<<endl;
	u.d=1.2345;
	cout<<"u.d="<<u.d<<endl;
	size=sizeof(u.d);
	cout<<"sizeof(u.d)="<<size<<endl;
	cout<<"s.i="<<s.i<<endl;
	cout<<"s.d="<<s.d<<endl;
	size=sizeof(struct s_tag);
	cout<<"sizeof(struct s_tag)="<<size<<endl;
}