ListIn this example, we create a list of integers and use the FirstOrDefault method to find the first even number in the list. The package library for these classes is System.Collections.Generic, which is included in the .NET Framework Class Library.myList = new List { 1, 2, 3, 4 }; int firstEven = myList.FirstOrDefault(x => x % 2 == 0); Console.WriteLine(firstEven); // output: 2