C++中重载、重写（覆盖）和隐藏的区别实例分析

class A{
public:
  void test(int i);
  void test(double i);
  void test(int i, double j);
  void test(double i, int j);
  int test(int i);         //错误，非重载
};

#include<iostream>
using namespace std;
class A{
public:
  void fun1(int i, int j){
    cout << "A::fun1() : " << i << " " << j << endl;
  }

};
class B : public A{
public:
    //隐藏
  void fun1(double i){
    cout << "B::fun1() : " << i << endl;
  }
};
int main(){
  B b;
    b.fun1(5);          //调用B类中的函数
  b.fun1(1, 2);        //出错，因为基类函数被隐藏
  system("pause");
  return 0;
}    

#include<iostream>
using namespace std;
class A{
public:
  virtual void fun3(int i){
    cout << "A::fun3() : " << i << endl;
  }

};
class B : public A{
public:
    //重写
  virtual void fun3(double i){
    cout << "B::fun3() : " << i << endl;
  }
};
int main(){
    A a;
  B b;
  A * pa = &a;
  pa->fun3(3);
  pa = &b;
  pa->fun3(5);
  system("pause");
  return 0;
}

#include<iostream>
using namespace std;
class A{
public:
  void fun1(int i, int j){
    cout << "A::fun1() : " << i << " " << j << endl;
  }
  void fun2(int i){
    cout << "A::fun2() : " << i << endl;
  }
  virtual void fun3(int i){
    cout << "A::fun3(int) : " << i << endl;
  }
};
class B : public A{
public:
    //隐藏
  void fun1(double i){
    cout << "B::fun1() : " << i << endl;
  }
    //重写
  void fun3(int i){
    cout << "B::fun3(int) : " << i << endl;
  }
    //隐藏
  void fun3(double i){
    cout << "B::fun3(double) : " << i << endl;
  }
};
int main(){
  B b;
  A * pa = &b;
  B * pb = &b;
  pa->fun3(3);        //重写，多态性，调用B的函数
  b.fun3(10);         //隐藏，调用B的函数
  pb->fun3(20);       //隐藏，调用B的函数
  system("pause");
  return 0;
}

B::fun3(int) : 3
B::fun3(int) : 10
B::fun3(int) : 20
请按任意键继续. . .