what is iterator in c++?
// C++ program to demonstrate iterators
#include <iostream>
#include <vector>
using namespace std;
int main()
{
// Declaring a vector
vector<int> v = { 1, 2, 3 };
// Declaring an iterator
vector<int>::iterator i;
int j;
cout << "Without iterators = ";
// Accessing the elements without using iterators
for (j = 0; j < 3; ++j)
{
cout << v[j] << " ";
}
cout << "\nWith iterators = ";
// Accessing the elements using iterators
for (i = v.begin(); i != v.end(); ++i)
{
cout << *i << " ";
}
// Adding one more element to vector
v.push_back(4);
cout << "\nWithout iterators = ";
// Accessing the elements without using iterators
for (j = 0; j < 4; ++j)
{
cout << v[j] << " ";
}
cout << "\nWith iterators = ";
// Accessing the elements using iterators
for (i = v.begin(); i != v.end(); ++i)
{
cout << *i << " ";
}
return 0;
}