Question

这是我的程序的工作方式。它会提示用户输入，一旦检测到非数字，循环将停止。这是我的代码：

int size = 0;
float number;
float total = 0;
vector <float> data;

//prompt user to enter file name
string file;
cout << "Enter a file name : " ;
cin >> file ;
//concatenate the file name as text file
file += ".txt";

//Write file
cout << "Enter number : ";
ofstream out_file;
out_file.open(file);
while(cin >> number)
{
    data.push_back(number);
    size++;
}

cout<< "Elements in array are : " ;
//check whether is there any 0 in array else print out the element in array
for (int count = 0; count < size; count++)
{
    if (data.size() == 0)
    {
        cout << "0 digit detected. " << endl;
        system("PAUSE");
    }else
    {
        //write the element in array into text file
        out_file << data.size() << " " ;
        cout << data.size() << " ";
    }
}
out_file.close();

但是，有一些错误。例如，我输入1,2,3,4,5，g，它应该将数组写为1,2,3,4,5到文本文件中。但是，它用5,5,5,5,5代替。我想知道我是否错误地使用了push_back？任何指南都将不胜感激。

提前致谢。

Answer 1

此行是您出错的地方：

out_file << data.size() << " " ;

您只是插入向量的大小而不是条目中的数据...

（实际上你只是在输出循环中检查data.size()）

Answer 2

for (int count = 0; count < data.size(); count++) {
     if (data[count] == 0) {
         cout << "0 digit detected. " << endl;
         system("PAUSE");
     } else {
         //write the element in array into text file
         out_file << data[count] << " " ;
         cout << data[count] << " ";
     }
 }
 out_file.close();

使用元素而不是向量的大小。例如：

std::vector<int> yourVector;

yourVector.push_back(1);
yourVector.push_back(3);

cout << "My vector size: " << yourVector.size() << endl; //This will give 2

cout << "My vector element: " << yourVector[0] << endl; //This will give 1

cin用C ++进行矢量化

2 个答案: