c# how to find an item in a list code example

Example 1: find a value in list of objects in c#

var item = TextPool.FirstOrDefault(o => o.Name == "test");
if (item != null)
       item.value = "Value";

Example 2: c# find element in list of list

var element = (from sublist in userList
               from item in sublist
               where item.uniqueidentifier == someid
               select item).FirstOrDefault();