iterator for 2d vector

Question

How to create iterator/s for 2d vector (a vector of vectors)?

Answer 1

Suppose you have a vector like this:-

vector > vect{{1,2,3},{4,5,6},{7,8,9}};

Now to use iterators with 2D vectors :-

 for(auto i = vect.begin() ; ibegin() ; jend() ; j++)
        cout << *j <<" ";
     cout <<"\n";  
     //similarly you can do other things
  }

Also other shorter way is

 for(auto i : vect)
  {
     for(auto j : i)
        cout << j <<" ";
     cout << "\n";
//similarly you can do other things also.
  }

Please note the way of calling variables is different in both the cases.