Input file reading wrong value and eof controlled loop does not end - c++

Question

I'm attempting to read data from an input file using a loop that should stop at the end of the file within a function. The data in the file is arranged in lines like this:
Zip Drive
89
Warehouse C
75.89
Keyboard
133
Warehouse C
25.95
On the fourth line the variable is filled with some garbage input and everything read after is blank. The loop also will not end.
int ReadData(string productName[], string productLocation[], int productQty[], double productPrice[])
{
ifstream infile;
int i = 0;
infile.open("prog1.txt");
do {
getline(infile, productName[i]);
infile >> productQty[i];
getline(infile, productLocation[i]);
infile >> productPrice[i];
i++;
} while (!infile.eof());
infile.close();
return i;
}

Answer 1

The infile >> productQty[i] and infile >> productPrice[i] statements are reading int/double values and leaving the line breaks after them in the stream, to be read by the next std::getline() call, which is not what you want to happen.
You need to either:
use std::getline() to read every line, and then use std::istringstream to parse the int/double values from their respective lines:
int ReadData(string productName[], string productLocation[], int productQty[], double productPrice[])
{
ifstream infile("prog1.txt");
int i = 0;
while (getline(infile, productName[i]))
{
getline(infile, line);
istringstream(line) >> productQty[i];
getline(infile, productLocation[i]);
getline(infile, line);
istringstream(line) >> productPrice[i];
++i;
}
infile.close();
return i;
}
call infile.ignore() after reading the int/double values, to read and dismiss the line breaks:
int ReadData(string productName[], string productLocation[], int productQty[], double productPrice[])
{
ifstream infile("prog1.txt");
int i = 0;
while (getline(infile, productName[i]))
{
infile >> productQty[i];
infile.ignore(numeric_limits<streamsize>::max(), '\n');
getline(infile, productLocation[i]);
infile >> productPrice[i];
infile.ignore(numeric_limits<streamsize>::max(), '\n');
++i;
}
infile.close();
return i;
}
In either case, the arrays must be pre-allocated with enough elements to hold as many products as are in the file. Since the code has no way of actually verifying that count, I would suggest an alternative safer approach:
struct productInfo
{
string name;
string location;
int quantity;
double price;
};
istream& operator>>(istream &in, productInfo &out)
{
string line;
if (!getline(in, out.name)) {
// don't set failbit yet, in case this is just EOF...
return in;
}
// at this point, a new product is encountered, so
// any missing data is considered a failure...
if (!getline(in, line)) {
in.setstate(failbit);
return in;
}
if (!(istringstream(line) >> out.quantity)) {
in.setstate(failbit);
return in;
}
if (!getline(in, out.location)) {
in.setstate(failbit);
return in;
}
if (!getline(in, line)) {
in.setstate(failbit);
return in;
}
if (!(istringstream(line) >> out.price)) {
in.setstate(failbit);
return in;
}
return in;
}
int ReadData(vector<productInfo> &products)
{
ifstream infile("prog1.txt");
int i = 0;
productInfo info;
while (infile >> info)
{
products.push_back(info);
++i;
}
infile.close();
return i;
}