Citing the official javadoc of List.addAll
:
Appends all of the elements in the specified collection to the end of
this list, in the order that they are returned by the specified
collection's iterator (optional operation). The behavior of this
operation is undefined if the specified collection is modified while
the operation is in progress. (Note that this will occur if the
specified collection is this list, and it's nonempty.)
So you will copy the references of the objects in list
to anotherList
. Any method that does not operate on the referenced objects of anotherList
(such as removal, addition, sorting) is local to it, and therefore will not influence list
.