Can you list the main data structures implemented through collections in the standard library?

The standard Java library implements the main data structures through the java.util package, which are represented as collections. Here are the key ones:

• List — an ordered set of elements allowing duplicates. Implementations:

  • ArrayList — dynamic array
  • LinkedList — doubly linked list

• Set — a collection of unique elements, without a specific order (or with ordering in some implementations):

  • HashSet — based on hash table
  • LinkedHashSet — preserves insertion order
  • TreeSet — sorted set

• Queue — a queue, usually for processing elements in FIFO order:

  • LinkedList (implements Queue)
  • PriorityQueue — a priority queue

• Map — key-value mapping:

  • HashMap — hash table
  • LinkedHashMap — preserves insertion order
  • TreeMap — sorted by key map

These data structures allow efficient storage and processing of collections of objects in Java.