Collections (Lists, Maps, Sets)

Overview

Java Collections Framework provides data structures like Lists, Maps, and Sets.

Topics

• List (ArrayList, LinkedList)
• Map (HashMap, TreeMap)
• Set (HashSet, TreeSet)

Examples

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

Map<String, Integer> scores = new HashMap<>();
scores.put("Alice", 90);
scores.put("Bob", 85);

Set<Integer> uniqueNumbers = new HashSet<>();
uniqueNumbers.add(1);
uniqueNumbers.add(2);
uniqueNumbers.add(1); // Duplicate, won't be added

Tags

#java #collections #lists #maps #sets #arraylist #hashmap #hashset