@@ -4,3 +4,5 @@ add_executable(cpp-inheritance-main main.cpp)
 add_executable(cpp-inheritance inherit.cpp)
 add_executable(cpp-inheritances inherits.cpp)
 add_executable(cpp-inheritance-method inherit-method.cpp)
+add_executable(cpp-inheritance-virtual inherit-virtual.cpp)
+add_executable(cpp-inheritance-polymorphism polymorphism.cpp)
@@ -0,0 +1,181 @@
+//
+// Created by zing on 6/7/2020.
+//
+
+#include <iostream>
+
+using namespace std;
+
+class Animal {
+public:
+    int m_Age;
+};
+
+//继承前加virtual关键字后，变为虚继承
+//此时公共的父类Animal称为虚基类
+class Sheep : virtual public Animal {
+};
+
+class Tuo : virtual public Animal {
+};
+
+class SheepTuo : public Sheep, public Tuo {
+};
+
+void test01() {
+    SheepTuo st;
+    st.Tuo::m_Age = 200;
+    st.Sheep::m_Age = 100;
+
+    cout << "st.Sheep::m_Age = " << st.Sheep::m_Age << endl;
+    cout << "st.Tuo::m_Age = " << st.Tuo::m_Age << endl;
+    cout << "st.m_Age = " << st.m_Age << endl;
+}
+
+
+class Animal2 {
+public:
+    //Speak函数就是虚函数
+    //函数前面加上virtual关键字，变成虚函数，那么编译器在编译的时候就不能确定函数调用了。
+    virtual void speak() {
+        cout << "动物在说话" << endl;
+    }
+};
+
+class Cat : public Animal2 {
+public:
+    void speak() {
+        cout << "小猫在说话" << endl;
+    }
+};
+
+class Dog : public Animal2 {
+public:
+
+    void speak() {
+        cout << "小狗在说话" << endl;
+    }
+
+};
+//我们希望传入什么对象，那么就调用什么对象的函数
+//如果函数地址在编译阶段就能确定，那么静态联编
+//如果函数地址在运行阶段才能确定，就是动态联编
+
+void DoSpeak(Animal2 &animal) {
+    animal.speak();
+}
+//
+//多态满足条件：
+//1、有继承关系
+//2、子类重写父类中的虚函数
+//多态使用：
+//父类指针或引用指向子类对象
+
+void test02() {
+    Cat cat;
+    DoSpeak(cat);
+
+    Dog dog;
+    DoSpeak(dog);
+}
+
+//普通实现
+class Calculator {
+public:
+    int getResult(string oper) const {
+        if (oper == "+") {
+            return m_Num1 + m_Num2;
+        } else if (oper == "-") {
+            return m_Num1 - m_Num2;
+        } else if (oper == "*") {
+            return m_Num1 * m_Num2;
+        }
+        //如果要提供新的运算，需要修改源码
+    }
+
+public:
+    int m_Num1;
+    int m_Num2;
+};
+
+void test03() {
+    //普通实现测试
+    Calculator c;
+    c.m_Num1 = 10;
+    c.m_Num2 = 10;
+    cout << c.m_Num1 << " + " << c.m_Num2 << " = " << c.getResult("+") << endl;
+    cout << c.m_Num1 << " - " << c.m_Num2 << " = " << c.getResult("-") << endl;
+    cout << c.m_Num1 << " * " << c.m_Num2 << " = " << c.getResult("*") << endl;
+}
+
+
+//多态实现
+//抽象计算器类
+//多态优点：代码组织结构清晰，可读性强，利于前期和后期的扩展以及维护
+class AbstractCalculator {
+public :
+
+    virtual int getResult() {
+        return 0;
+    }
+
+    int m_Num1;
+    int m_Num2;
+};
+
+//加法计算器
+class AddCalculator : public AbstractCalculator {
+public:
+    int getResult() {
+        return m_Num1 + m_Num2;
+    }
+};
+
+//减法计算器
+class SubCalculator : public AbstractCalculator {
+public:
+    int getResult() {
+        return m_Num1 - m_Num2;
+    }
+};
+
+//乘法计算器
+class MulCalculator : public AbstractCalculator {
+public:
+    int getResult() {
+        return m_Num1 * m_Num2;
+    }
+};
+
+
+void test04() {
+    //创建加法计算器
+    AbstractCalculator *abc = new AddCalculator;
+    abc->m_Num1 = 10;
+    abc->m_Num2 = 10;
+    cout << abc->m_Num1 << " + " << abc->m_Num2 << " = " << abc->getResult() << endl;
+    delete abc;  //用完了记得销毁
+
+    //创建减法计算器
+    abc = new SubCalculator;
+    abc->m_Num1 = 10;
+    abc->m_Num2 = 10;
+    cout << abc->m_Num1 << " - " << abc->m_Num2 << " = " << abc->getResult() << endl;
+    delete abc;
+
+    //创建乘法计算器
+    abc = new MulCalculator;
+    abc->m_Num1 = 10;
+    abc->m_Num2 = 10;
+    cout << abc->m_Num1 << " * " << abc->m_Num2 << " = " << abc->getResult() << endl;
+    delete abc;
+}
+
+
+int main() {
+    test01();
+    test02();
+    test03();
+    test04();
+    return 0;
+}