List in Java

What is a List?

• List is an interface in the Java Collection Framework that stores an ordered collection of elements and allows duplicates, and elements can be accessed by their index.
  *Maintains insertion order.
  *Allows duplicate elements.
  *Supports index-based access.

Why List?

-1. Order is Important

Data should maintain insertion order.

1. Duplicates Are Allowed

Example: Same product added twice in the cart.

1. Index-Based Access Needed

You can access elements using an index:

When List?

• When the number of elements is unknown


• When duplicates are allowed


• When we need ordered data


• When we need index-based operations

*** Real-Time Examples

• E-commerce Cart

Use List → Products in cart (order matters)

• Student Marks

Store multiple marks (duplicates allowed)

• Log History

Maintain insertion order