day7: homework 修改第7题

day7/homework/h7.cpp

@@ -131,5 +131,10 @@ int main()
         cout << "dynamic_cast 将 Dog 转换为 Animal 失败" << endl;
     }
 
+    delete ap;
+    delete ap2;
+    delete cp2;
+    delete dp2;
+
     return 0;
 }

day7/homework/h7_2.cpp

@@ -0,0 +1,105 @@
+#include <iostream>
+#include <typeinfo>
+
+class Animal
+{
+public:
+    virtual ~Animal() {}
+};
+
+class Cat : public Animal
+{
+public:
+    void meow()
+    {
+        std::cout << "Meow!" << std::endl;
+    }
+};
+
+class Dog : public Animal
+{
+public:
+    void bark()
+    {
+        std::cout << "Woof!" << std::endl;
+    }
+};
+
+int main()
+{
+    // 任务1：将Animal类型指针转换为Cat类型指针
+    Animal *animal1 = new Cat();
+    try
+    {
+        Cat *cat = dynamic_cast<Cat *>(animal1);
+        if (cat)
+        {
+            cat->meow();
+        }
+        else
+        {
+            throw 1;
+        }
+    }
+    catch (int e)
+    {
+        std::cout << "转换失败：无法将Animal类型转换为Cat类型。" << std::endl;
+    }
+
+    // 任务2：将Animal类型指针转换为Dog类型指针
+    Animal *animal2 = new Dog();
+    try
+    {
+        Dog *dog = dynamic_cast<Dog *>(animal2);
+        if (dog)
+        {
+            dog->bark();
+        }
+        else
+        {
+            throw 2;
+        }
+    }
+    catch (int e)
+    {
+        std::cout << "转换失败：无法将Animal类型转换为Dog类型。" << std::endl;
+    }
+
+    // 任务3：将Cat类型指针转换为Animal类型指针
+    Cat *cat2 = new Cat();
+    try
+    {
+        Animal *animal3 = dynamic_cast<Animal *>(cat2);
+        if (animal3)
+        {
+            std::cout << "转换成功：Cat类型成功转换为Animal类型。" << std::endl;
+        }
+    }
+    catch (const std::bad_cast &e)
+    {
+        std::cout << "转换失败：" << e.what() << std::endl;
+    }
+
+    // 任务4：将Dog类型指针转换为Animal类型指针
+    Dog *dog2 = new Dog();
+    try
+    {
+        Animal *animal4 = dynamic_cast<Animal *>(dog2);
+        if (animal4)
+        {
+            std::cout << "转换成功：Dog类型成功转换为Animal类型。" << std::endl;
+        }
+    }
+    catch (const std::bad_cast &e)
+    {
+        std::cout << "转换失败：" << e.what() << std::endl;
+    }
+
+    // 释放内存
+    delete animal1;
+    delete animal2;
+    delete cat2;
+    delete dog2;
+
+    return 0;
+}