Question

I am trying to use LINQ to return the an element which occurs maximum number of times AND the number of times it occurs.

For example:
I have an array of strings:

string[] words = { "cherry", "apple", "blueberry", "cherry", "cherry", "blueberry" };

//...
Some LINQ statement here
//...

In this array, the query would return cherry as the maximum occurred element, and 3 as the number of times it occurred. I would also be willing to split them into two queries if that is necessary (i.e., first query to get the cherry, and second to return the count of 3.

Answer 1

var topWordGroup = words.GroupBy(word => word).OrderByDescending(group => group.Count()).FirstOrDefault();
// topWordGroup might be a null!
string topWord = topWordGroup.Key;
int topWordCount = topWordGroup.Count;

And in case if we don’t like O(N log N):

var topWordGroup = words.GroupBy(word => word).Aggregate((current, acc) => current.Count() < acc.Count() ? acc : current);