Question

I was wondering how I would go about splitting a text file, chunk by chunk, and storing groups of lines as a single string.. For example:

I have a text file of questions, some of which are multiple lines. After a variable number of lines (depending on how many lines the question takes up) there is a blank line, then the answer, followed by another question (which could also be longer than 1 line), blank line, answer.

Something like this, where "q" are lines that should be stored as a single string and "a" should also be a single string:

qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq

aaaaaaaaaaaaaaaaaaaaaaa

qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq

aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

I tried reading line by line, combining string line + line if line != "". But it got confusing and messy and I couldn’t ever get it to work correctly.

I simply want to store the first set of q‘s as a single string and put it in vector[0] and the first set of a‘s in vector[1]. The second set of q‘s in vector[2]. The second set of a‘s in vector[3].. and so on. Both the q’s and the a’s can be several lines.

---

Any suggestions or help will be much appreciated!

#include <vector>
#include <fstream>
#include <iostream>
#include "Question.h"
#include <iomanip>

using namespace std;

int main(int argc, char * argv[]){
    ifstream infile;
    string filename = "questions.txt";//manually set for testing.

    //cout<<"Enter the questions file: ";
    //cin>>filename;

    infile.open(filename.c_str());

    if (!infile){
            cout<<"error"<<endl;
            return 0;
    }
    else {
            cout<<"file opened!"<<endl;
    }
    vector<string> myvector;

    string line;
    string additionalLine;
    int totalLines = 0;
    while(getline(infile,line)){
            totalLines++;
    }
    cout<<"total lines: "<<totalLines<<endl;

/*
    while(getline(infile,line,'\n')){
            cout<<line<<endl;
    }
*/

    while(getline(infile,line,\n)){
            if (line == ""){
                    cout<<"empty"<<endl;
            }

            else {
                    cout<<"line is not empty"<<endl;
                    additionalLine = additionalLine + line;
            }
            if (line != ""){
                    myvector.push_back(additionalLine);
            }

    }

    for(int i=0; i < (myvector.size()); i++){
            cout<<myvector[i]<<endl;
    }

    //TESTING
    cout<<"Question: "<<endl;
    cout<<myvector[0]<<endl;
    cout<<"Answer: "<<endl;
    cout<<myvector[1]<<endl;

    return 0;

}

Answer 1

I tweaked the code a bit and got it to work!

I changed the way I approached cycling through the lines of the text file, changing it to while (!infile.eof()) and manually got the lines. I also added a statement to detect if there was a new line. I also had to reposition where I reset the string variables back to “”.

Thanks for the suggestions! Heres the solution code:

#include <vector>
#include <fstream>
#include <iostream>
#include "Question.h"
#include <iomanip>

using namespace std;

int main(int argc, char * argv[]){
    ifstream infile;
    string filename = "questions.txt";//manually set for testing.

    //cout<<"Enter the questions file: ";
    //cin>>filename;

    infile.open(filename.c_str());

    if (!infile){
            cout<<"error"<<endl;
            return 0;
    }
    else {
            cout<<"file opened!"<<endl;
    }
    vector<string> myVec;

    string line;
    string comboLine="";

    while(!infile.eof()){
            getline(infile,line);

            if (line == "" || line == "\0")  {
                    //cout<<"->BLANK LINE DETECTED<-"<<endl;
                    myVec.push_back(comboLine);
                    comboLine="";
            }else {
                    comboLine = comboLine + line;
                    //cout<<"comb: "<<comboLine<<endl;
            }

            line = "";

    }
    infile.close();

    //TESTING
    cout<<"Question: "<<endl;
    cout<<myVec[0]<<endl;
    cout<<"Answer: "<<endl;
    cout<<myVec[1]<<endl;
    cout<<"Question 2: "<<endl<<myVec[2]<<endl;
    cout<<"Answer 2: "<<endl<<myVec[3]<<endl;
    return 0;

}