1 #include <iostream> 2 using namespace std; 3  4 class MyClass 5 { 6 public: 7     int a; 8     void method(); 9 };10 void MyClass::method()11 {12     cout<<"the last value of class:a after fun:"<<a<<‘\n‘;13 }14 15     void fun1(MyClass);16     void fun2(MyClass*);17     void fun3(MyClass&);18 int main()19 {20     MyClass myclass;21     myclass.a=10;22     fun1(myclass);23     cout<<" the initial value of class:a after fun1:  "<<myclass.a<<‘\n‘;24     myclass.a=10;25     fun2(&myclass);26     cout<<" the initial value of class:a after fun2:  "<<myclass.a<<‘\n‘;27     myclass.a=10;28     fun3(myclass);29     cout<<" the initial value of class:a after fun3:  "<<myclass.a<<‘\n‘;30     system("pause");31 }32 void fun1(MyClass mc)33 {34     mc.a=40;35     mc.method();36 }37 void fun2(MyClass* mc)38 {39     mc->a=60;40     mc->method();41 }42 void fun3(MyClass&mc)43 {44     mc.a=80;45     mc.method();46 }