[Don’t .NET] Last() at last!

Although LinkedLists may not be your go-to data structure, you might find yourself using the Last property to access the tail of the list like this:

LinkedList<int> list = [];
LinkedListNode<int> lastNode = list.Last;
Console.WriteLine(lastNode);//Outputs nothing, since list.Last is null

However, you can also use the Last() method, which will throw an InvalidOperationException if the list is empty:

LinkedList<int> list = [];
int lastValue = list.Last();//Throws InvalidOperationException: Sequence contains no elements
Console.WriteLine(lastValue);

If the list contains elements, Last() will return the last element's value:

LinkedList<int> list = [];
list.AddLast(0);
int lastValue = list.Last();
Console.WriteLine(lastValue);//Outputs 0

This behavior is explained by the fact that the Last property of LinkedList and the Last method from LINQ are different. While it can be a bit convoluted, understanding this distinction is crucial for effective usage.

References:

LinkedList Class (System.Collections.Generic)

Enumerable.Last Method (System.Linq)