day7/homework/h7.cpp

@@ -44,7 +44,6 @@ catch (int e)
 ********************************************************************/
 
 #include <iostream>
-#include <typeinfo>
 
 using namespace std;
 
@@ -75,66 +74,52 @@ public:
 int main()
 {
     Animal *ap = new Animal(); // 创建一个 Animal 类型的指针
-
     try
     {
         Cat *cp = dynamic_cast<Cat *>(ap); // 将其转换为 Cat 类型的指针
-        if (cp)
         cp->meow();
-        else
-            throw 1;
     }
-    catch (int &e)
+    catch (int e)
     {
-        cout << "dynamic_cast 将 Animal 转换为 Cat 失败" << endl;
+        cout << "dynamic_cast 将 Animal 转换为 Cat 失败" << endl
+             << e << endl;
     }
 
     Animal *ap2 = new Animal(); // 创建一个 Animal 类型的指针
     try
     {
         Dog *dp = dynamic_cast<Dog *>(ap2); // 将其转换为 Dog 类型的指针
-        if (dp)
         dp->bark();
-        else
-            throw 1;
     }
-    catch (int &e)
+    catch (int e)
     {
-        cout << "dynamic_cast 将 Animal 转换为 Dog 失败" << endl;
+        cout << "dynamic_cast 将 Animal 转换为 Dog 失败" << endl
+             << e << endl;
     }
 
     Cat *cp2 = new Cat(); // 创建一个 Cat 类型的指针
     try
     {
         Animal *ap3 = dynamic_cast<Animal *>(cp2); // 将其转换为 Animal 类型的指针
-        if (ap3)
         cout << "dynamic_cast 将 Cat 转换为 Animal 成功" << endl;
-        else
-            throw 1;
     }
-    catch (int &e)
+    catch (int e)
     {
-        cout << "dynamic_cast 将 Cat 转换为 Animal 失败" << endl;
+        cout << "dynamic_cast 将 Cat 转换为 Animal 失败" << endl
+             << e << endl;
     }
 
     Dog *dp2 = new Dog(); // 创建一个 Dog 类型的指针
     try
     {
         Animal *ap4 = dynamic_cast<Animal *>(dp2); // 将其转换为 Animal 类型的指针
-        if (ap4)
         cout << "dynamic_cast 将 Dog 转换为 Animal 成功" << endl;
-        else
-            throw 1;
     }
-    catch (int &e)
+    catch (int e)
     {
-        cout << "dynamic_cast 将 Dog 转换为 Animal 失败" << endl;
+        cout << "dynamic_cast 将 Dog 转换为 Animal 失败" << endl
+             << e << endl;
     }
 
-    delete ap;
-    delete ap2;
-    delete cp2;
-    delete dp2;
-
     return 0;
 }

day7/homework/h7_2.cpp

@@ -1,105 +0,0 @@
-#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;
-}