When should you use an iterator? And is it used at all?

Question

Kotlin

Well, I can go through the elements, I can find out if there is a next element, I can even go backwards in the listiterator, but for what? I can also use the for loop and go through the elements, and check if there is a next element.

Answer 1

The for loop, all of a sudden, uses an iterator, it's just syntactic sugar to it. Also, a raw iterator can be useful if you need to change the list during iteration (for example, remove elements).
Also, for example, you can implement extensions like

val Fragment.parents: Iterable<Fragment>
Или
val ViewGroup.children: Iterable<View>

, which will allow, with the overhead of a couple of small objects, to conveniently work with entities that are not intended for iteration.