What is the best way to traverse an array in forward and reverse order? What is the best way to traverse vector in forward and reverse order?

Question

C++ / C#

What is the best way to traverse an array in forward and reverse order?
What is the best way to traverse std::vector forward and backward?
What is the best way to traverse the array in forward and reverse order, but not from the beginning and from the end, but from the i-th to the j-th?
What is the best way to traverse std::vector in forward and reverse order, but not from the beginning and from the end, but from the i-th to the j-th?
I just don't like mixing int and size_t.

Answer 1

For vectors, use iterators. For arrays - indexes.