Set Interface - Notes By ShariqSP

Set Interface in Java

The Set interface in Java represents a collection of unique elements, i.e., it does not allow duplicate elements. It does not maintain the insertion order of elements.

Methods:

• add(E element): Adds the specified element to the set if it is not already present.
• remove(Object obj): Removes the specified element from the set if it is present.
• contains(Object obj): Returns true if the set contains the specified element.
• isEmpty(): Returns true if the set contains no elements.
• size(): Returns the number of elements in the set.
• clear(): Removes all elements from the set.

Implementation Classes:

The Set interface has several implementation classes in Java:

• HashSet: Hash table-based implementation of the Set interface.
• LinkedHashSet: Hash table and linked list implementation of the Set interface, with predictable iteration order.
• TreeSet: Red-Black tree implementation of the Set interface, sorted according to the natural ordering of its elements or by a custom comparator.