Thread: I would like some clarification regarding this iterator code.

Can anyone explain why the author of this tutorial initially uses rbegin() but subsequently uses begin()?

I thought the objective here was to be able to count backwards through the use of an iterator.

Code:

#include <iostream>
#include <vector>

int main ()
{
  std::vector<int> myvector (5);  // 5 default-constructed ints

  int i=0;

  std::vector<int>::reverse_iterator rit = myvector.rbegin();
  for (; rit!= myvector.rend(); ++rit)
    *rit = ++i;

  std::cout << "myvector contains:";
  for (std::vector<int>::iterator it = myvector.begin(); it != myvector.end(); ++it)
    std::cout << ' ' << *it;
  std::cout << '\n';

  return 0;
}

The first loop starts from the end of the vector (vector.at(4) and assigns values to the array. So vector.at(4) contains 1, at.(2) contains 3, etc. The second loop starts at the beginning of the vector printing each element.

Jim

Can anyone explain this piece of code?

*rit = ++i;