c++ - 需要帮助解决内存泄漏

Question

我正在编写一个使用对象的动态数组的库存管理系统。这样做的策略不是使用 vector ，而是分配一个动态数组，每次客户端需要添加到库存时，该数组都会递增 1。我收到“段错误”错误，所以我认为这是内存泄漏。

我曾尝试重写它以匹配地址，但没有成功。我认为 buildItem 函数会产生一个临时对象，该对象会在函数结束时被销毁。不过我不知道如何解决这个问题。

#include <iomanip>
#include <iostream>
#include <string>
using namespace std;

class InventoryObject {
private:
  int itemNumber;
  string description;
  int qty;
  float price;

public:
  int getItemNum() { return itemNumber; }
  string getDescription() { return description; }
  int getQty() { return qty; }
  float getPrice() { return price; }

  void storeInfo(int p, string d, int q, float pr);
  void showValues(InventoryObject &item);
};

// Function Implementation
void InventoryObject::storeInfo(int p, string d, int q, float pr) {
  itemNumber = p;
  description = d;
  qty = q;
  price = pr;
}

void InventoryObject::showValues(InventoryObject &item) {
  cout << fixed << showpoint << setprecision(2) << endl;
  cout << "Part Number  : " << item.getItemNum() << endl;
  cout << "Description  : " << item.getDescription() << endl;
  cout << "Quantity:    : " << item.getQty() << endl;
  cout << "Price        : " << item.getPrice() << endl << endl;
}

// Function Prototypes for Client Program
InventoryObject buildItem();
void drawMenu();
void showValues(InventoryObject &);
void printInventory(int size);

int main() {
  int size = 1;
  int choice;
  bool quit = false;
  InventoryObject part;
  InventoryObject *iArray = new InventoryObject[size];
  drawMenu();
  cin >> choice;
  while (quit == false) {
    if (choice == 1) {
      InventoryObject item;
      item = buildItem();
      iArray[size] = item;
    }
    if (choice == 2) {
      iArray[size].showValues(iArray[size]);
    }
    if (choice == 3) {
      quit = true;
    }
  }

  return 0;
}

// This function accepts the data from the client and creates a new
// InventoryObject object. The object is then supposed to be added to the
// dynamic array.
InventoryObject buildItem() {
  InventoryObject *tempObject = new InventoryObject;
  int itemNum;
  string description;
  int qty;
  float price;

  cout << "Enter data for the item you want to enter:\n\n";
  cout << "Item Number: \n";
  cin >> itemNum;
  cout << "Description: \n";
  cin.get();
  getline(cin, description);
  cout << "Quantity: \n";
  cin >> qty;
  cout << "Unit price: \n";
  cin >> price;

  tempObject->storeInfo(itemNum, description, qty, price);
  return *tempObject;
}

void drawMenu() {
  cout << "1. Add Inventory\n";
  cout << "2. Display Inventory\n";
  cout << "3. Quit Program\n";
}

我希望创建对象并将其放入动态数组中。然后重新绘制菜单并从那里与客户端交互。

Answer 1

主要问题是您写入的内存超出了为数组 (iArray) 分配的内存区域。

具体来说，这行代码:

iArray[size] = item;

实际上应该是:

iArray[size - 1] = item;

---

上述不会导致内存泄漏，但您在程序中做的其他事情会:

您的函数 buildItem 在返回指针值而不先删除指针时执行此操作。

要解决此问题，请更改

InventoryObject *tempObject = new InventoryObject;

到

InventoryObject tempObject;

最后，记得在 main 中 return 0; 之前删除 iArray

delete[] iArray