Question

这是我得到的错误： Exercise11.cxx：29：13：错误：二进制表达式的操作数无效（＆＃39; ostream＆＃39;（又名＆＃39; basic_ostream＆＃39;）和＆＃39; vector＆＃39;）

#include <iostream> 
#include <vector>
#include <iomanip>

using namespace std;
int main()
{
   cout << "Kaitlin Stevers" << endl;
   cout << "Exercise 11 - Vectors" << endl;
   cout << "November 12, 2016" <<endl;
   cout << endl;
   cout << endl;
   int size;
   cout << " How many numbers would you like the vector to hold? " << endl;
   cin >> size;
   vector<int> numbers;
   int bnumbers;

   for (int count = 0; count < size; count++)
   {
       cout << "Enter a number: " << endl;
       cin >> bnumbers;
       numbers.push_back(bnumbers); 
    }
    //display the numbers stored in order
    cout << "The numbers in order are: " << endl;
    for(int i=0; i < size; i++)
    {
        cout<<numbers[i]<< " ";
    }
    cout << endl;
   return 0;
}

错误出现在代码中：

cout << numbers << endl;

第二个问题：

我如何使用vent.reverse（）;反转矢量然后显示它。

Answer 1

错误告诉您需要知道的所有内容：operator<<和std::cout之间未定义std::vector。

失败的一行就是这一行......

cout << numbers << endl;

...因为cout是ostream而numbers是vector。 Here's a list of supported types that can be streamed into ostream.

考虑使用for循环打印出numbers的内容：

cout << "The numbers in order are: " << endl;

for(const auto& x : numbers)
{ 
    cout << x << " ";
}

cout << endl;

如果您无法访问C ++ 11功能，请强烈考虑研究它们并更新编译器。如果符合C ++ 03标准，则代码如下：

cout << "The numbers in order are: " << endl;

for(std::size_t i = 0; i < numbers.size(); ++i)
{ 
    cout << numbers[i] << " ";
}

cout << endl;

Answer 2

您无法调用cout << numbers，因为没有定义的方法来输出矢量。如果要打印出矢量中的数据，则需要迭代并分别打印每个元素。有关详细信息How to print out the contents of a vector?

Answer 3

您必须使用循环来打印矢量：

for(int i=0; i < size; i++){
    cout<<numbers[i]<< " ";
}

Answer 4

另一种方法，使用C ++ 11功能

public class MainActivityFragment extends Fragment {

    private ArrayAdapter<String> mForecastAdapter;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container);

        ArrayList<String> weekForecast = new ArrayList<>();

        weekForecast.add("Today - Sunny - 88/63");
        weekForecast.add("Tomorrow - Foggy - 70/40");
        weekForecast.add("Weds - Cloudy - 72/63");
        weekForecast.add("Thurs - Asteroids - 75/65");
        weekForecast.add("Fri - Heavy Rain - 65/56");
        weekForecast.add("Sat - HELP TRAPPED IN WEATHERSTATION - 60/51");
        weekForecast.add("Sun - Sunny - 80/68");

        mForecastAdapter = new ArrayAdapter<>(getActivity(),
                R.layout.list_item_forecast, R.id.list_item_forecast_textview, weekForecast);

        ListView listView = (ListView) rootView.findViewById(R.id.listview_forecast);
        listView.setAdapter(mForecastAdapter);

        //return inflater.inflate(R.layout.fragment_main, container, false);
        return rootView;
    }
}

错误消息/用户输入数字的向量

4 个答案: