public abstract class Stuff { int hp; int atk; int def; int money; int exp; }

这是一个抽象类Stuff，它定义了5个属性：hp、atk、def、money、exp。这些属性可以被它的子类继承和使用，但是这个类本身不能被实例化。

由于这个类是抽象类，可能还包含了一些抽象方法，这些方法只有方法名，没有方法体。它告诉子类必须实现这些方法。抽象方法的定义方式是在方法名前面加上abstract关键字，例如：

public abstract void attack();

这个抽象方法attack()没有方法体，它只是告诉子类必须实现这个方法。子类必须重写这个方法，并且提供自己的实现。这样可以约束子类的行为，使得子类更加符合预期的功能。

相关问题

#include<iostream> using namespace std; class Iceman { public: int num; int hp; int atk; static int totalNum; Iceman(int n, int h, int a) { num = n; hp = h; atk = a; totalNum++; } }; int Iceman::totalNum = 0; int main() { Iceman* red_iceman[100]; int Iceman_totalNum = 0; int current_hp = 3; red_iceman[Iceman_totalNum] = new Iceman(Iceman::totalNum + 1, current_hp, 0); Iceman_totalNum++; cout << " red iceman " << " born with strength " << red_iceman[Iceman_totalNum]->hp << "," << Iceman_totalNum << " iceman in red headquarter" << endl; }这段代码有什么问题

这段代码存在两个问题：

1. 当访问 `red_iceman[Iceman_totalNum]->hp` 时，`Iceman_totalNum` 的值已经被加 1，导致访问到了一个未初始化的指针，会导致程序崩溃。

2. 在使用 `new` 运算符为 `red_iceman[Iceman_totalNum]` 分配内存时，没有检查是否超出了数组 `red_iceman` 的边界，可能会导致程序崩溃或者出现未定义的行为。

下面是修改后的代码：

#include<iostream>
using namespace std;

class Iceman {
public:
    int num;
    int hp;
    int atk;
    static int totalNum;
    Iceman(int n, int h, int a) {
        num = n;
        hp = h;
        atk = a;
        totalNum++;
    }
};

int Iceman::totalNum = 0;

int main() {
    Iceman* red_iceman[100];
    int Iceman_totalNum = 0;
    int current_hp = 3;
    red_iceman[Iceman_totalNum] = new Iceman(Iceman::totalNum + 1, current_hp, 0);
    Iceman_totalNum++;
    cout << " red iceman "  << " born with strength " << red_iceman[Iceman_totalNum - 1]->hp << "," << Iceman_totalNum << " iceman in red headquarter" << endl;

    delete red_iceman[Iceman_totalNum - 1]; // 释放内存
    return 0;
}

在这个修改后的代码中，我们使用 `Iceman_totalNum - 1` 来访问刚刚新建的 `Iceman` 对象的 `hp` 属性，避免了上面提到的第一个问题。同时，在分配内存前，我们需要先检查 `Iceman_totalNum` 是否超出了数组 `red_iceman` 的边界，避免了第二个问题。最后，为了避免内存泄漏，我们使用 `delete` 运算符释放了分配的内存。

#include<iostream> using namespace std; class Iceman { public: int num; int hp; int atk; int sword = 0; int bomb = 0; int arrow = 0; static int totalNum; Iceman(int n, int h, int a) { num = n; hp = h; atk = a; totalNum++; } }; int Iceman::totalNum = 0; int main() { Iceman* red_iceman[100]; int Iceman_totalNum = 0; int current_hp = 3; red_iceman[Iceman_totalNum] = new Iceman(Iceman::totalNum + 1, current_hp, 0); Iceman_totalNum++; cout << " red iceman " << " born with strength " << red_iceman[Iceman_totalNum]->hp << "," << Iceman_totalNum << " iceman in red headquarter" << endl; }这段代码有什么问题

这段代码有两个问题：

1. 在输出语句中，`red_iceman[Iceman_totalNum]`已经是指向新创建的Iceman对象的指针，因此应该使用`->`而不是`.`来访问`hp`成员变量。正确的输出语句应该是：

   cout << " red iceman "  << " born with strength " << red_iceman[Iceman_totalNum]->hp << "," << Iceman_totalNum << " iceman in red headquarter" << endl;

2. 在创建Iceman对象时，构造函数中的`totalNum++`语句应该在其他语句之前执行，否则创建的第一个Iceman对象的编号会是0而不是1。正确的构造函数应该是：

   Iceman(int n, int h, int a) {         
       totalNum++;  
       num = n;         
       hp = h;         
       atk = a;         
   }