How to check if two sequences have the same elements?

Short answer: How to check if two sequences have the same elements regardless of order and duplicates? var list1 = new[] {1, 2, 3, 4}; var list2 = new[] {4, 3, 2, 1}; bool areEqual = !list1.Except(list2).Any() && !list2.Except(list1).Any(); Console.WriteLine(areEqual); // Output: True Explanation: This checks if both lists contain the same elements, ignoring order and duplicates.

Real-world example (ShopNest)

ShopNest uses LINQ to query orders: filter by date, project to a summary DTO, and order by total—readable C# that becomes SQL under EF Core.

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.