Java collections

Category : Java | Sub Category : Java.util Package | By Prasad Bonam Last updated: 2023-07-12 10:55:57 Viewed : 583

Java collections:

Java collections provide a set of classes and interfaces that allow you to work with groups of objects as a single unit. These collections provide various data structures and algorithms to store, manipulate, and process data efficiently. Here are some commonly used Java collections:

1. List:

   • List is an ordered collection that allows duplicate elements. It provides methods to add, access, modify, and remove elements at specific positions. Some commonly used list implementations are ArrayList, LinkedList, and Vector.

2. Set:

   • Set is a collection that does not allow duplicate elements. It provides methods to add, access, and remove elements efficiently. Some commonly used set implementations are HashSet, TreeSet, and LinkedHashSet.

3. Map:

   • Map is a key-value pair-based collection. It stores elements as key-value pairs and allows fast retrieval of values based on keys. Map does not allow duplicate keys but allows duplicate values. Some commonly used map implementations are HashMap, TreeMap, and LinkedHashMap.

4. Queue:

   • Queue is a collection that follows the FIFO (First-In-First-Out) principle. It provides methods to add elements to the end of the queue and remove elements from the front. Some commonly used queue implementations are LinkedList, ArrayDeque, and PriorityQueue.

5. Deque:

   • Deque (Double-ended queue) is a collection that allows insertion and removal of elements from both ends. It can be used as a queue or a stack. Some commonly used deque implementations are LinkedList and ArrayDeque.

6. Stack:

   • Stack is a collection that follows the LIFO (Last-In-First-Out) principle. It provides methods to push elements onto the stack and pop elements from the top. The Stack class is commonly used to implement stack functionality.

These collections are part of the java.util package and provide a wide range of functionality for working with data in Java. Each collection has its own characteristics, such as ordering, uniqueness, and efficiency, which make them suitable for different use cases. Choosing the appropriate collection depends on your specific requirements and the operations you need to perform on the data.