How to read in user entered comma separated integers?

Question

I\'m writing a program that prompts the user for:

1. Size of array
2. Values to be put into the array

First part is fine, I create a dynamica

Answer 1

All of the existing answers are excellent, but all are specific to your particular task. Ergo, I wrote a general touch of code that allows input of comma separated values in a standard way:

template<class T, char sep=','>
struct comma_sep { //type used for temporary input
    T t; //where data is temporarily read to
    operator const T&() const {return t;} //acts like an int in most cases
};
template<class T, char sep>
std::istream& operator>>(std::istream& in, comma_sep<T,sep>& t) 
{
    if (!(in >> t.t)) //if we failed to read the int
        return in; //return failure state
    if (in.peek()==sep) //if next character is a comma
        in.ignore(); //extract it from the stream and we're done
    else //if the next character is anything else
        in.clear(); //clear the EOF state, read was successful
    return in; //return 
}

Sample usage http://coliru.stacked-crooked.com/a/a345232cd5381bd2:

typedef std::istream_iterator<comma_sep<int>> istrit; //iterators from the stream
std::vector<int> vec{istrit(in), istrit()}; //construct the vector from two iterators

Since you're a beginner, this code might be too much for you now, but I figured I'd post this for completeness.

Answer 2

You can use getline() method as below:

#include <vector>
#include <string>
#include <sstream>

int main() 
{
  std::string input_str;
  std::vector<int> vect;

  std::getline( std::cin, input_str );

  std::stringstream ss(str);

  int i;

  while (ss >> i)
  {
    vect.push_back(i);

    if (ss.peek() == ',')
    ss.ignore();
  }
}

The code is taken and processed from this answer.

Answer 3

#include<bits/stdc++.h>
using namespace std;
int a[1000];
int main(){
    string s;
    cin>>s;
    int i=0;
    istringstream d(s);
    string b;
    while(getline(d,b,',')){
        a[i]= stoi(b);
        i++;
    }
    for(int j=0;j<i;j++){
        cout<<a[j]<<" ";
    }
}

This code works nicely for C++ 11 onwards, its simple and i have used stringstreams and the getline and stoi functions