Introduction to Programming

Removing elements

There are four methods in the Set interface that remove (delete) elements:

• remove(E): It removes the provided element and returns true if the list contained it
• removeAll(Collection): It removes the provided elements and returns true if the list has changed
• retainAll(Collection): It removes all the elements that are not in the provided collection and returns true if the list has changed
• removeIf(Predicate<? super E> filter): It removes all the elements that for which the provided predicate returns true

The first three methods behave the same way as with the List collection, so we will not repeat the explanations(see the subsection Remove elements of the section List – ArrayList preserves order).

As for the last of the listed ...