C++ infile提取检查是否为int

Question

我是 C++ 的新手，不知道从哪里开始，或者是否可能，但我正在尝试检查长度、宽度、半径等是否实际上是 double ，如果不是返回 0。

int main() {

ifstream inFile;
ofstream outFile;

string in;
double length, width, tLength = 0, tWidth = 0, areaRec, tAreaRec = 0, parameter, tParameter = 0; 
double radius, tRadius = 0, areaCirc, tAreaCirc = 0, circumference, tCircumference = 0;
double  savings, tSavings = 0; 
int people = 0, age, tAge = 0;

string name1, name2;

inFile.open("inData_with_error.txt");

outFile.open("outData_Normal.txt");
outFile << fixed << showpoint << setprecision(2);

if (!inFile) {
    cout << "ERROR: Unable to open file!" << endl;
    inFile.close();
}
else {
    cout << "Caculating..." << endl;

    while (inFile >> length >> width >> radius >> name1 >> name2 >> age >> savings) {
        cout << length << ", " << width << ", " << radius << ", " << name1 << ", " << name2 << ", " << age << ", " << savings << endl;

        tLength = tLength + length;
        tWidth = tWidth + width;

        parameter = length * 2 + width * 2;
        areaRec = length * width;
        tParameter = tParameter + parameter;
        tAreaRec = tAreaRec + areaRec;

        tRadius = tRadius + radius;

        areaCirc = pow(radius, 2) * PI;
        circumference = (radius * 2) * PI;
        tAreaCirc = tAreaCirc + areaCirc;
        tCircumference = tCircumference + circumference;

        people = people + 1;

        tAge = tAge + age;
        tSavings = tSavings + savings;
    }
}
cout << "Done" << endl;

outFile << "Rectangle:" << endl  << "Total length = " << tLength << ", " << "Total width = " << tWidth << ", " << "Total area = " << tAreaRec << ", " << "Total parameter = " << tParameter << endl << endl

<< "Circle:" << endl << "Total radius = " << tRadius << ", " << "Total area = " << tAreaCirc << ", " << "Total circumference = " << tCircumference << endl << endl

<< "Person: " << endl << "Total number of persons = " << people << endl << "Total age = " << tAge << endl << "Total savings = " << tSavings << endl;

inFile.close();
outFile.close();
system("pause");
return 0;

例如，如果我的错误数据如下所示，我想捕获字符和字符串并返回 0，但不知道如何解决这个问题。有人可以引导我走向正确的方向吗？

10.45 aaaa
13.78

Jake Melon 45
7600

128 76.9
;

Mike Sander 23
800

15.9 43
w

David James i
87000.54

Answer 1

在 while 循环结束后，您可以添加一个测试来检查 while 循环是否由于 EOF 或读取错误而终止数据。

while (inFile >> length >> width >> radius >> name1 >> name2 >> age >> savings) { ... }

if ( inFile.eof() )
{
   // No errors in reading data
}
else
{
   // Error in reading data.
   // Deal with error
}