C++:当使用从对象的getter方法调用的值时，输出一个随机的负整数？

Question

以下是我的文件TotalTemplate.cpp:

#include <iostream>
#include "conio.h"

using namespace std;

template<class T>
class TotalTemplate{
public:
//protected:
    T* items;
    int itemsAdded;
    int amountOfItems;

//public:

    //Exception for trying to add items when its passed its limit
    class TooManyItems{ };

    //Exception for trying to call total before the total has been reached
    class IncompleteTotal{ };

    TotalTemplate(int amountOfItems){
        TotalTemplate::amountOfItems = amountOfItems;
        items = new T[amountOfItems];
        itemsAdded = 0;
    }

    TotalTemplate(int amountOfItems, T firstItem){
        TotalTemplate::amountOfItems = amountOfItems;
        items[] = new T[amountOfItems];
        items[0] = firstItem;
        itemsAdded = 1;
    }

    void addItem(T item){
        if (itemsAdded >= amountOfItems)
            throw TooManyItems();
        else{
            items[itemsAdded-1] = item;
            itemsAdded++;
        }
    }

    //Returns the amount of items added so far
    int getAmountAdded(){
        return itemsAdded;
    }

    T getTotal(){//Here is the method definition that is giving me problems
        if (itemsAdded < amountOfItems)
            throw IncompleteTotal();
        else{
            T total=items[0];
            for (int i = 1; i < itemsAdded; i++)
                total += items[i];
            return total;
        }
    }


};


void main(){
    //using int to fill the generic type T
    cout << "Enter the amount of items to be totaled: ";
    int totalAmountOfItems = getInt();
    TotalTemplate<int> *total=new TotalTemplate<int>(totalAmountOfItems);
    while (true){
        cout << total->getAmountAdded() << " items added so far!\nSelect one of the following actions to take.\n";
        cout << "(1) Add an item.\n";
        cout << "(2) View total.\n";
        cout << "(3) Exit Program.\n";
        switch (menuSelect(3)){
        case 1://Add an item
            try{
                cout << "Enter a number to add: ";
                int item = getInt();
                total->addItem(item);
            }
            catch (TotalTemplate<int>::TooManyItems){
                cout << "\nItems given exceeds expected limit.\n\n";
            }
            break;

        case 2://View Total
            try{
                int totalInt = total->getTotal(); //Here is my problem
                cout << "The total is: " << totalInt << endl<<endl;
            }
            catch (TotalTemplate<int>::IncompleteTotal){
                cout << "\nRunning Total has not yet reached total amount of items yet.\n\n";
            }
            break;

        case 3: //Exit program
            return;
        }
    }
         cout << "\n\nExiting program...";
         _getch();
}

我遇到的问题是在 main 方法中，当我调用 total.getTotal() 时，我没有返回预期的 int，而是所有项目加在一起的总和，我得到了一个完全随机的 int 输出:- 842150451

我的猜测是它正在输出一些东西而不是从 getTotal() 返回的值，但我不确定如何或为什么或如何修复它。我来自 Java 背景，所以我觉得我不习惯做不正确的 oop C++ 练习。

此外，getInt() 和 menuSelect() 是我在之前的代码中多次重复使用的方法，因此为了简单起见，我将它们从文件中排除。

有人知道我做错了什么吗？

Answer 1

addItem中的这一行

items[itemsAdded-1] = item;

应该是

items[itemsAdded] = item;