What is the hierarchy of the Collections API in Java…

The Collections API in Java is a unified architecture for storing and processing groups of objects. It includes a number of interfaces and their implementations, providing standard ways to manipulate collections.

Main interfaces:

Collection: The root interface of the hierarchy. Defines basic operations.
List: An ordered collection. Elements have indices, duplicates are allowed.
Set: A collection that does not allow duplicates. The order of elements is not guaranteed.
SortedSet: A Set whose elements are sorted.
Map: A collection of key-value pairs. Keys are unique, values can repeat. Does not extend Collection.

Common implementations:

For List: ArrayList, LinkedList.
For Set: HashSet, LinkedHashSet.
For SortedSet: TreeSet.
For Map: HashMap, LinkedHashMap, TreeMap.

Hierarchy of wrapper classes:

Collections: A utility static class containing algorithms for collections (sort, shuffle, etc.) and factory methods for creating synchronized and immutable collections.

Example usage:

// Creating an ArrayList
List<String> names = new ArrayList<>();
names.add("Alice");
names.add("Bob");

// Iterating over elements
for (String name : names) {
    System.out.println(name);
}

// Working with HashSet
Set<Integer> numbers = new HashSet<>();
numbers.add(10);
numbers.add(20);
numbers.add(10); // Duplicate is ignored

// Working with HashMap
Map<String, Integer> ages = new HashMap<>();
ages.put("Alice", 30);
ages.put("Bob", 25);

Using the Collections API ensures code consistency and simplifies data handling.

What is the hierarchy of the Collections API in Java?