Vector, iterators and const_iterator

Question

I have just started learning vectors and iterators. I can't understand 2 things. Why can I change the constant iterator and what is the role of the "*"?

#include <iostream>
#include <string>
#include <vector>
using namespace std;
int main()
{
    vector<string> inventory;
    inventory.push_back("inventory1");
    inventory.push_back("inventory2");
    inventory.push_back("inventory3");
    vector<string>::iterator myIterator;
    vector<string>::const_iterator iter;
    cout << "Your items:\n";
    for (iter = inventory.begin(); iter != inventory.end(); iter++)
    {
        cout << *iter << endl;
    }

Answer 1

When you do iter = inventory.begin() it makes iter refer to the first string in your vector. iter++ moves it to refer to the next string.

In the output you use *iter as way to access the string that iter refers to. In the first output that will be inventory1.

The slight confusion about the constness is that

vector<string>::const_iterator   iter;

is an iterator that refers to things that are constant, while

const vector<string>::iterator   iter;

would make the iterator itself constant, but allow you to modify the object it refers to.