C++: Read from text file and separate into variable

Question

I have this in a text file:

John 20 30 40
mike 30 20 10

How do i read from the text file and separate them into variable name, var1, var2,

Answer 1

I think that when the numbers were printed out in a group with no spaces, the reason was just that you need to put spaces in between the variable, like this:

cout << name << " " << var1 << " " << var2 << " " << var3 << "\n";

Answer 2

It looks like you need to declare var1, var2, and var3.

Also instead of this:

      getline (myfile,name,'\t');
      getline (myfile,var1,'\t');
      getline (myfile,var2,'\t');
      getline (myfile,var3,'\t');

Try this:

  myfile >> name;
  myfile >> var1;
  myfile >> var2;
  myfile >> var3;

Not because what you had is wrong, but the second is cleaner and will handle all white space.

Answer 3

Something like this should work (I don't have a compiler handy, so you may need to tweak this a little):

#include <iostream>
#include <sstream>
using namespace std;


int main()
{
    ifstream inputFile("marks.txt");
    string line;

    while (getline(inputFile, line))
    {
        istringstream ss(line);

        string name;
        int var1, var2, var3;

        ss >> name >> var1 >> var2 >> var3;
    }
}

Edit: Just saw this again, I don’t know why I chose the get line approach earlier. Doesn’t the following (simpler solution) work?

#include <fstream>
using namespace std;

int main()
{ 
    ifstream fin(“marks.txt”);

    string name;
    int var1;
    int var2;
    int var3;

    while (fin >> name >> var1 >> var2 >> var3)
    {
        /* do something with name, var1 etc. */
        cout << name << var1 << var2 << var3 << “\n”;
    }
}