Using getline in loop, storing to an array - c++

Question

Using getline to store information, I want to have an array which store a whole column in a text file, using a '/' as the delimiter, but when creating a loop which goes through the first line and stores that in a[i] etc, then moves onto the next line.`
const int MAX = 20;
int main(){
string menuname;
string a[MAX];
string d[MAX];
string b[MAX];
string c[MAX];
string line;
bool error = false;
ifstream openFile;
int counter = 0;
do{
cout << "Please enter the name of the menu you would like to open: ";
cin >> menuname;
menuname += ".txt";
openFile.open(menuname.c_str());
if(openFile.fail()){
cerr << "Unable to open file, please re-enter the name.\n";
error = true;
}
//Determine how many lines long the text file is
while(getline(openFile, line)){
++counter;
}
//Testing the counter
cout << counter;
}while(error == true);
while(! openFile.eof()){
for(int i = 0; i < counter; i++){
getline( openFile, a[i], '/');
getline( openFile, b[i], '/');
getline( openFile, c[i], '/');
getline( openFile, d[i]);
}
}
for(int i = 0; i < counter; i++){
cout << a[i] << b[i];
}
}
There is currently no errors when i run the program, and I have tested the counter variable by just showing an output, which is working correctly, but at the bottom of the program I have created a small test which should print some 2 of the arrays I store, but it prints nothing and the program just ends after displaying the value of counter.

Answer 1

The problem is you are at the end of the file when you go to actually store the data.
while(getline(openFile, line)){
++counter;
}
Reads the file all the way to the end and then sets the EOF flag on the string. Then you get to
while(! openFile.eof()){
for(int i = 0; i < counter; i++){
getline( openFile, a[i], '/');
getline( openFile, b[i], '/');
getline( openFile, c[i], '/');
getline( openFile, d[i]);
}
}
And since the EOF flag is set the while loop is never executed. Since all you really need counter for is the the display loop at the end we can combine the counter loop and the reading loop into one loop like
while(getline( openFile, a[counter], '/') && getline( openFile, b[counter], '/') &&
getline( openFile, c[counter], '/') && getline( openFile, d[counter])){
counter++;
}
And now we read in the full file and get a count of the number of lines read.