Collection Interface

java.util.Collection<E> is the root interface that almost every collection type in Java implements. It defines the common vocabulary every implementation must support: adding items, removing items, asking how many there are, checking membership, and walking through them. This lesson covers what Collection actually requires from its implementations, the methods used day to day, how iteration plugs in through Iterable, the default methods added in Java 8, and why writing code against Collection rather than against a specific class is a useful habit.