getline() problem

[andrew rober]

over here in this code

// example about structures
#include <iostream>
#include <string>
#include <sstream>
using namespace std;

struct movies_t {
  string title;
  int year;
} mine, yours;

void printmovie (movies_t movie);

int main ()
{
  string mystr;

  mine.title = "2001 A Space Odyssey";
  mine.year = 1968;

  cout << "Enter title: ";
  getline (cin,yours.title);
  cout << "Enter year: ";
  getline (cin,mystr);
  stringstream(mystr) >> yours.year;

  cout << "My favorite movie is:\n ";
  printmovie (mine);
  cout << "And yours is:\n ";
  printmovie (yours);
  return 0;
}

void printmovie (movies_t movie)
{
  cout << movie.title;
  cout << " (" << movie.year << ")\n";
}

getline (cin,mystr);
stringstream(mystr) >> yours.year;
why should i define a new string then use it instead of just saying
getline (cin,yours.year);
when i replace the new getline i give me an error at c++ visual studio 2010
HOWEVER it dont give any errors while using cin >> yours.year
so whats wrong with getline function over here ? does it always need a string not integer so we use string in the middle to use it ?

[shacktar]

does it always need a string not integer so we use string in the middle to use it ?

Yes, std::getline takes a string as a second parameter so if you want to get an integer using getline, then you have to read a temporary string and convert. You're right that if all you want is an integer, then cin>> is fine. However, cin>> leaves a newline in the stream. getline on the other hand reads everything up to and including the newline (assuming you didn't use the other form that takes in a delimiter). I believe that they used getline in this example for symmetricity of the input statements (and for not having to worry about cleaning up the newline).