of characters. It provides methods for appending, inserting, deleting, and modifying character sequences efficiently. 82. What is the purpose of the "HashSet" class in Java? The "HashSet" class in Java is an implementation of the Set interface that stores unique elements in no particular order. It provides constant-time performance for basic operations like adding, removing, and checking for the presence of elements. 83. What is the purpose of the "HashMap" class in Java? The "HashMap" class in Java is an implementation of the Map interface that stores key value pairs. It provides fast retrieval and insertion of elements based on their keys and allows for efficient mapping and lookup operations. 84. What is the purpose of the "LinkedList" class in Java? The "LinkedList" class in Java is an implementation of the List interface that uses a doubly-linked list to store elements. It provides efficient insertion and removal of elements at both ends of the list but slower random access.
85. What is the purpose of the "Comparator" interface in Java? The "Comparator" interface in Java is used to define custom ordering of objects. It provides a way to compare objects based on specific criteria other than their natural ordering defined by the "Comparable" interface. 86. What is the purpose of the "Comparable" interface in Java? The "Comparable" interface in Java is used to define the natural ordering of objects of a class. It provides a method, "compareTo()", that allows objects to be compared and sorted based on their natural order. 87. What is the purpose of the "super" keyword in Java? The "super" keyword in Java is used to refer to the superclass of a class or to call the