Set Interface HashSet TreeSet

Set Interface

Collections without duplicate elements.

Set Examples

Set hashSet = new HashSet<>();
Set treeSet = new TreeSet<>();

hashSet.add("Java");
hashSet.add("Java"); // Duplicate ignored

treeSet.add("Zebra");
treeSet.add("Apple"); // Sorted order

Key Points

• HashSet: unordered, fastest operations.
• TreeSet: sorted, slower operations.
• LinkedHashSet: maintains insertion order.
• Elements must override equals() hashCode().