1. Iterator

2. iterator is an object that traverse a container, like string or lists.
The most fundamental methods provided by an iterator are hasNext(), which returns a boolean value indicating whether the container has more elements or not, and next(), which returns an element in that container, and then move to the next.
Java has a built-in iterator class and many classes, like arrayList, have an associated iterator.

3. Loop through a list Useful info:
Java provides a simpler way to loop through a list, the for each loop
The common usage is like
for(datatype element: list){
(loop body) }
Useful info:
de/language/foreach.html