Parsing string in C++ - c++

Question

Currently,
I have this string us,muscoy,Muscoy,CA,,34.1541667,-117.3433333.
I need to parse US and CA. I was able to parse US correctly by this:
std::string line;
std::ifstream myfile ("/Users/settingj/Documents/Country-State Parse/worldcitiespop.txt");
while( std::getline( myfile, line ) )
{
while ( myfile.good() )
{
getline (myfile,line);
//std::cout << line << std::endl;
std::cout << "Country:";
for (int i = 0; i < 2/*line.length()*/; i++)
{
std::cout << line[i];
}
}
}
But i'm having an issue parsing to CA.
Heres some code I dug up to find the amount of ',' occurrences in a string but I am having issues saying "parse this string between the 3rd and 4th ',' occurrence.
// Counts the number of ',' occurrences
size_t n = std::count(line.begin(), line.end(), ',');
std::cout << n << std::endl;

Answer 1

You can use boost::split function (or boost::tokenizer) for this purpose. It will split string into vector<string>.
std::string line;
std::vector<std::string> results;
boost::split(results, line, boost::is_any_of(","));
std::string state = results[3];

Answer 2

It's not for a class... Haha... it seems like a class question though...
I have the solution:
int count = 0;
for (int i = 0; i < line.length(); i++)
{
if (line[i] == ',')
count++;
if (count == 3){
std::cout << line[i+1];
if (line[i+1] == ',')
break;
}
}
Just had to think about it more :P

Answer 3

This is STL version, works pretty well for simple comma separated input files.
#include<fstream>
#include <string>
#include <iostream>
#include<vector>
#include<sstream>
std::vector<std::string> getValues(std::istream& str)
{
std::vector<std::string> result;
std::string line;
std::getline(str,line);
std::stringstream lineS(line);
std::string cell;
while(std::getline(lineS,cell,','))
result.push_back(cell);
return result;
}
int main()
{
std::ifstream f("input.txt");
std::string s;
//Create a vector or vector of strings for rows and columns
std::vector< std::vector<std::string> > v;
while(!f.eof())
v.push_back(getValues(f));
for (auto i:v)
{
for(auto j:i)
std::cout<<j<< " ";
std::cout<<std::endl;
}
}