using getline to get multiple lines from a file and input them in different arrays

Question

I'm trying to do a simple getline from a filestream and then store the different input into different arrays.

The input file is something like this.

Course Of Sales Time,Price ($),Volume,Value ($),Condition 10/10/2013 04:57:27 PM,5.81,5000,29050.00,LT XT 10/10/2013 04:48:05 PM,5.81,62728,364449.68,SX XT 10/10/2013 04:10:33 PM,.00,0,.00,

Note that the first two lines are redundant and should be ignored. All data should be stored in their respective arrays like time[i], price[i].

string datefield;
int count = 0;
string date[5000];
float pricefield;
float price [5000];
int volume[5000];
float value[5000];
string condition[5000];
int i = 0;

while (!infile.eof()) {
    count++;
    getline(infile,datefield);
    while (count >= 2) {
        getline(infile,date[i], ',');
        infile  >> price[i] >> volume[i];
        i++;
        break;
    }
}

The problem here is, no input is going into volume[i].

First: while (!infile.eof()) is wrong. You never check a single extraction in this code for validity before assuming it worked. — WhozCraig
– WhozCraig, Commented Feb 19, 2014 at 17:58

Community · Accepted Answer · 2017-05-23 10:31:56Z

1

Don't put eof() in the while condition. It's wrong! Check out: Why is iostream::eof inside a loop condition considered wrong?. To work out, you can change
```
while (!infile.eof()) {
    count++;
    getline(infile,datefield);
    ... 
```
to
```
while (getline(infile,datefield)) {
    count++;
    ... 
```
You should be very careful in the data reading step. For ",.00,0,.00,", as there is no spaces within it, thus >> price[i] >> volume[i] will try to read all these content to price[i]. No content will be read into volume[i]. To work out, you can first read this part to a string and then read the data from it by splitting. Or replace all ',' to spaces and then put it into a std::istringstream, then you can use >> price[i] >> volume[i] correctly.

edited May 23, 2017 at 10:31

CommunityBot

11 silver badge

answered Feb 19, 2014 at 18:18

herohuyongtao

50.9k30 gold badges138 silver badges179 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

using getline to get multiple lines from a file and input them in different arrays

1 Answer 1

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related