如何获取C++动态数组的大小

我正在学习 C++，我需要创建结构Airplane并与之合作。

我的结构飞机.h

#include "stdafx.h"
using namespace std;

struct Airplane {
    string destination;
    int number;
    string type;
};

这是我的代码

#include "stdafx.h"
#include "Airplane.h"

string SetDestination(int n);
string SetType(int n);
void PrintAirplaneList(Airplane * &airplaneList, int n, string title);
void SortByDestination (Airplane *&airplaneList, int n);
void FindAirplanesAndPrint(Airplane *&airplaneList, int n, string type);

int _tmain(int argc, _TCHAR* argv[])
{
using namespace std;

srand((unsigned)time(NULL));

int n;
cout << "Input n = ";
cin >> n;

Airplane * airplaneList = new Airplane[n];

for (int i = 0; i < n; ++i)
{
    airplaneList[i].destination = SetDestination(rand()%5);
    airplaneList[i].number = rand()%9001 + 1000;
    airplaneList[i].type = SetType(rand()%3);
}

PrintAirplaneList(airplaneList, n, "List:");
SortByDestination (airplaneList, n);
PrintAirplaneList(airplaneList, n, "Sorted list (by destination):");

string type;
cout << "Input type: ";
getline(cin, type);
FindAirplanesAndPrint(airplaneList, n, type);

delete [] airplaneList;

system("PAUSE");
return 0;
}

string SetDestination (int n)
{
    string destination;
    switch(n){
    case 0: destination = "Tokio"; break;
    case 1: destination = "Amsterdam"; break;
    case 2: destination = "Moscow"; break;
    case 3: destination = "Philadelphia"; break;
    case 4: destination = "San Diego"; break;
    default: destination = "Unknown city"; break;
    }
    return destination;
}

string SetType (int n)
{
    string type;
    switch(n){
    case 0: type = "passenger"; break;
    case 1: type = "cargo"; break;
    case 2: type = "post"; break;
    default: type = "unknown type"; break;
    }
    return type;
}

void PrintAirplaneList(Airplane *&airplaneList, int n, string title)
{
    cout << "\n";
    cout << title << "\n\n";
    for (int i = 0; i < n; ++i)
    {
        cout << "Destination: " << airplaneList[i].destination << "\n";
        cout << "Number: " << airplaneList[i].number << "\n";
        cout << "Type: " << airplaneList[i].type << "\n\n";
    }
}

void SortByDestination (Airplane *&airplaneList, int n)
{
    for (int i = 0; i < n - 1; ++i)
    {
        for (int j = 0; j < n -1; ++j)
        {
            if(airplaneList[j + 1].destination > airplaneList[j].destination) continue;
            Airplane tempAirplane = airplaneList[j];
            airplaneList[j] = airplaneList[j + 1];
            airplaneList[j + 1] = tempAirplane;
        }
    }
}

void FindAirplanesAndPrint(Airplane *&airplaneList, int n, string type) {
    cout << "Type - " << type << "\n";
    int count = 0;
    for (int i = 0; i < n; ++i)
    {
        if (airplaneList[i].type == type)
        {
            cout << "Destination: " << airplaneList[i].destination << "\n";
            cout << "Number: " << airplaneList[i].number << "\n";
            ++count;
        }
    }
    if (count == 0)
    {
        cout << "Not found\n";
    }
}

我有两个问题。
1.我无法输入文字

string type;
cout << "Input type: ";
getline(cin, type);
FindAirplanesAndPrint(airplaneList, n, type);

和我的功能FindAirplanesAndPrint开始工作时没有任何类型值。如何让我的程序获得价值？
2. 如何在函数中获取动态数组的大小？因为看起来数组的传递大小n在每个函数中都是错误的方式。

“如何在函数中获取动态数组的大小？因为它似乎是数组的传递大小n在每个功能中都是错误的方式。”

然而，当您使用动态分配的 C 样式数组时，这是唯一的方法。

如果您想避免显式发送大小，则传递一些包装此原始内存缓冲区的对象并提供其他检索大小的方法。这里最合理的解决方案是使用std::vector<Airplane>.