List in Java

Source: Dev.to

What is a List?

List is an interface in the Java Collection Framework that stores an ordered collection of elements and allows duplicates. Elements can be accessed by their index.

• Maintains insertion order
• Allows duplicate elements
• Supports index‑based access

Why List?

• Order is important – data maintains insertion order.
• Duplicates are allowed – e.g., the same product added twice in a cart.
• Index‑based access needed – you can retrieve elements using an index.

When to Use a List?

• When the number of elements is unknown.
• When duplicates are allowed.
• When ordered data is required.
• When index‑based operations are needed.

Real‑Time Examples

• E‑commerce Cart – Use a List to store products in the cart (order matters).
• Student Marks – Store multiple marks, allowing duplicates.
• Log History – Maintain insertion order of log entries.