509.cpp

C++实训教程

/*
	509.cpp
	Written By S.Y.Feng
	DEMO 无名对象
*/
#include <iostream.h>
class C
{
	 int n;
public:
	  C(){ cout << "@C1\n";	 n = 1; }
	  C( int a ): n(a) {cout << "@C2\n";}
	  C( int a ,int b): n(a+b) {cout << "@C3\n";}
	  int Get(){ return n; }
};
void main()
{
   C o1,o2(2),o3(3,4);
   cout << o1.Get() << endl;
   cout << o2.Get() << endl;
   cout << o3.Get() << endl;
   cout << "下面使用无名对象"<<endl;

   o1 = C(11,0);
   o2 = C(22); //无名对象
   o3 = C();
   cout << o1.Get() << endl;
   cout << o2.Get() << endl;
   cout << o3.Get() << endl;
   o1 = (111,888);    //这是逗号表达式
   o2 = 222; //无名对象
   //o3 = ();
   cout << o1.Get() << endl;
   cout << o2.Get() << endl;
}
/*-
@C1
@C2
@C3
1
2
7
下面使用无名对象
@C3
@C2
@C1
11
22
1
@C2
@C2
888
222

*/