List and Set in Java

#beginners #computerscience #java #tutorial

Why do we use List and Set in Java?

Normal Arrays some limitations:

Array size is fixed and can not be changed dynamically.
There is no built-in control for handling duplicate elements.
Managing and manipulating data can be difficult.

So,we use List and Set in the Java collection Framework to manage data easily.

List in Java:

List is an interface in the Java collection Framework.

Features of List:

Maintain insertion order.
Allows duplicate elements.
Supports index-based access.
Dynamically resizes as needed.

List implementation classes:

ArrayList
LinkedList
Vector
Stack

ArrayList: Stores data using a dynamic array.
ArrayList<String> list = new ArrayList<>();
LinkedList: Stores data using a linked list structure.
LinkedList<String> list = new LinkedList<>();

Example:

Apple
Mango
Apple
Orange

Apple is repeated, so we can use a List.

Set in Java:

Set is an interface in the Java collection Framework.
Features of Set:
Does not allow duplicate elements.
Stores only unique value.
Provides efficient search and insertion operations.
Useful when uniqueness of data is required.

Set implementation classes:

HashSet:Stores unique elements and does not maintain insertion order.
Set<String> set = new HashSet<>();
LinkedHashSet: Stores unique elements and maintains insertion order.
Set<String> set = new LinkedHashSet<>();
TreeSet:Stores unique elements in sorted order.
Set<String> set = new TreeSet<>();

Example: