 Sentinel node may simplify certain list operations, by ensuring that the next or previous nodes exist for every element, and that even empty lists have at least one node.One may also use a sentinel node at the end of the list, with an appropriate data field, to eliminate some end-of-list tests.For example, when scanning the list looking for a node with a given value "x", setting the sentinel's data field to "x" makes it unnecessary to test for end-of-list inside the loop.