How to merge a list of lists with same type of items to a single list of items?
c#, lambda, linq
Solution
Use the SelectMany extension method
list = listOfList.SelectMany(x => x).ToList();
Problem
The question is confusing, but it is much more clear as described by the following code: ``` List<List<T>> listOfList; // add three lists of List<T> to listOfList, for example /* listOfList = new { { 1, 2, 3}, // list 1 of 1, 3, and 3 { 4, 5, 6}, // list 2 { 7, 8, 9} // list 3 }; */ List<T> list = null; // how to merger all the items in listOfList to list? // { 1, 2, 3, 4, 5, 6, 7, 8, 9 } // one list // list = ??? ``` Not sure if it possible by using C# LINQ or Lambda? Essentially, how can I concatenate or "flatten" a list of lists?