Question

I wrote the following code to read the content of a file:

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

int main(){
    char file_name[30] = "data.txt";
    // Create an ifstream to read the file.
    ifstream People_in(file_name);
      while (1) {
        if (People_in.eof())
            break;
        People_in >> first_name >> last_name >> age;
        cout << endl << "First Name: " << first_name;
        cout << endl << "Last Name:  " << last_name;
        cout << endl << "Enter Age:  " << age;
        cout << endl;

      }
      People_in.close();
      return 0;
  }

data.txt content:

FirstName1
LastName1
1
FirstName2
LastName2
2
FirstName3
LastName3
3

The output I expected:

First Name: FirstName1
Last Name: LastName1
Age: 1

First Name: FirstName2
Last Name: LastName2
Age: 2

First Name: FirstName3
Last Name: LastName3
Age: 3

But the output is:

First Name: FirstName1
Last Name: LastName1
Age: 1

First Name: FirstName2
Last Name: LastName2
Age: 2

First Name: FirstName3
Last Name: LastName3
Age: 3

First Name: FirstName3
Last Name: LastName3
Age: 3

I can’t figure out why?
PeopleIn is supposed to reach eof when it read through all the data. But how can it repeat the last 3 line ??

Answer 1

This is because after last step the eof is not reached (there is character after 3 in your file).

Try this:

while (People_in >> first_name >> last_name >> age)
{
    cout << endl << "First Name: " << first_name;
    cout << endl << "Last Name:  " << last_name;
    cout << endl << "Enter Age:  " << age;
    cout << endl;
}