Collections

A.k.a. the stuff in java.util.

What you learn in CSA

ArrayList<E>

That’s it.

😐

There’s a lot more

Interfaces

List<E>

Map<K, V>

Set<E>

Queue<E>

Deque<E>

Incidentally, why is there no Stack interface?

Some more important interfaces

Iterator<E>

Iterable<T> (in java.lang)

Important implementations

ArrayList<E> and LinkedList<E>

HashMap<K, V> and TreeMap<K, V>

HashSet<K, V> and TreeSet<K, V>

Other interesting implementations

LinkedHashMap<K,V>

LinkedHashSet<E>

Some other handy classes

Optional<E>

BitSet

PriorityQueue<E>

Collections of static methods

Arrays

Collections

Objects

Also a bunch of old garbage

Vector<E> (prefer ArrayList<E>)

Hashtable<K, V> (prefer Map<K, V>)

Stack<E> (prefer Deque<E>)

Enumeration<E> (prefer Iterator<E>)

Date and Calendar (prefer the java.time package)