Question

How do I write a C++ program to call a frequency table from a csv file, using vector?

Data given is in a csv file. Below is part of the sample data.

Student ID	English	Math	Science
100000100	80	90	90
100000110	70	60	70
100000120	80	100	90
100000130	60	60	60
100000140	90	80	80

Answer 1

#include <iostream>

#include <fstream>

#include <vector>

#include <iterator>

#include <string>

#include <algorithm>

#include <boost/algorithm/string.hpp>

/*

First, we will create a class to read frequency table from a csv file.

*/

class FileReader

{

std::string fileName;

std::string delimeter;

public:

FileReader(std::string filename, std::string delm = ",") :

fileName(filename), delimeter(delm)

{ }

// now we will create a Function to fetch frequency from a CSV File

std::vector<std::vector<std::string> > getData();

};

/*

* now we have to Parse through csv file line by line and returns the frequency data

* in vector of vector of strings.

*/

std::vector<std::vector<std::string> > FileReader::getData()

{

std::ifstream file(fileName);

std::vector<std::vector<std::string> > dataList;

std::string line = "";

// Iterate through each line and split the content using delimeter

while (getline(file, line))

{

std::vector<std::string> vec;

boost::algorithm::split(vec, line, boost::is_any_of(delimeter));

dataList.push_back(vec);

}

// Close the File

file.close();

return dataList;

}

int main()

{

// Creating an object of CSVWriter

FileReader reader("example.csv");

// Get the data from CSV File

std::vector<std::vector<std::string> > dataList = reader.getData();

// Print the content of row by row on screen

for(std::vector<std::string> vec : dataList)

{

for(std::string data : vec)

{

std::cout<<data << " , ";

}

std::cout<<std::endl;

}

return 0;

}