Parsing a comma-delimited std::string [duplicate]

Answer 1

std::string input="1,1,1,1,2,1,1,1,0";
std::vector<long> output;
for(std::string::size_type p0=0,p1=input.find(',');
        p1!=std::string::npos || p0!=std::string::npos;
        (p0=(p1==std::string::npos)?p1:++p1),p1=input.find(',',p0) )
    output.push_back( strtol(input.c_str()+p0,NULL,0) );

It would be a good idea to check for conversion errors in strtol(), of course. Maybe the code may benefit from some other error checks as well.

Answer 2

Simple Copy/Paste function, based on the boost tokenizer.

void strToIntArray(std::string string, int* array, int array_len) {
  boost::tokenizer<> tok(string);
  int i = 0;
  for(boost::tokenizer<>::iterator beg=tok.begin(); beg!=tok.end();++beg){
    if(i < array_len)
      array[i] = atoi(beg->c_str());
    i++;
}

Answer 3

simple structure, easily adaptable, easy maintenance.

std::string stringIn = "my,csv,,is 10233478,separated,by commas";
std::vector<std::string> commaSeparated(1);
int commaCounter = 0;
for (int i=0; i<stringIn.size(); i++) {
    if (stringIn[i] == ",") {
        commaSeparated.push_back("");
        commaCounter++;
    } else {
        commaSeparated.at(commaCounter) += stringIn[i];
    }
}

in the end you will have a vector of strings with every element in the sentence separated by spaces. empty strings are saved as separate items.

Answer 4

bool GetList (const std::string& src, std::vector<int>& res)
  {
    using boost::lexical_cast;
    using boost::bad_lexical_cast;
    bool success = true;
    typedef boost::tokenizer<boost::char_separator<char> > tokenizer;
    boost::char_separator<char> sepa(",");
    tokenizer tokens(src, sepa);
    for (tokenizer::iterator tok_iter = tokens.begin(); 
         tok_iter != tokens.end(); ++tok_iter) {
      try {
        res.push_back(lexical_cast<int>(*tok_iter));
      }
      catch (bad_lexical_cast &) {
        success = false;
      }
    }
    return success;
  }

Answer 5

This is the simplest way, which I used a lot. It works for any one-character delimiter.

#include<bits/stdc++.h>
using namespace std;

int main() {
   string str;

   cin >> str;
   int temp;
   vector<int> result;
   char ch;
   stringstream ss(str);

   do
   {
       ss>>temp;
       result.push_back(temp);
   }while(ss>>ch);

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

   return 0;
}

Answer 6

#include <sstream>
#include <vector>

const char *input = "1,1,1,1,2,1,1,1,0";

int main() {
    std::stringstream ss(input);
    std::vector<int> output;
    int i;
    while (ss >> i) {
        output.push_back(i);
        ss.ignore(1);
    }
}

Bad input (for instance consecutive separators) will mess this up, but you did say simple.