Question

Okay, so let’s say I have a List<car>. Each car also contains a List<part>. Each part has an ID associated with it. I’m only given the ID to a part, and I want to find the car that contains that part. What is the best way to find this car?

Answer 1

How about with LINQ?

List<Car> cars = ...
var carToFind = cars.FirstOrDefault(car => car.Parts.Any(part => part.Id == idToFind));

In English: “Find the first car (or null if no such car exists) that has any part with an Id matching the desired Id.”