Question

I have seen the code

vector<char> v(10);
vector<char>::iterator p;

here what is the need of vector<char>::.Does it mean iterator is a class inside vector namespace?

Answer 1

Does it mean iterator is a class inside vector namespace?

Not quite, is a type inside vector class template. The iterator not only depends on the type of container (here a vector), but on the type of element iterated over as well (here a char).