How does the Contains() method work in a List<T>?

Short answer: Contains(item) checks whether the item exists in the list. It uses Equals() internally.

Example code

bool exists = list.Contains(10); Note: For custom objects, override Equals() and GetHashCode().

Real-world example (ShopNest)

In ShopNest, an order page loads products with List<Product> so you can Add items to the cart and access them by index. Use IEnumerable<T> when you only need to loop (for example, printing invoice lines).

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.