What does Collection.Contains() use to check for existing objects?

Question

I have a strongly typed list of custom objects, MyObject, which has a property Id, along with some other properties.

Let\'s say that the

Answer 1

You can override Equals and GetHashCode, implement an IEqualityComparer and use that in the Contains call, or use an extension method like Any

if (!myList.Any(obj => obj.Property == obj2.Property && obj.Property2 == obj2.Property2))
   myList.Add(obj2);