Using Lambda Expressions To Count The Number Of Occurrences Of Values In A List

Question

I have a list that looks something like this . . .

List<string> l = new List<string>() { "A", "A", "A", "A", "B", "C", "C", "C", "C", "C", "D", "D" };

. . . and I want to end up with a dictionary that counts the number of occurrences of each value in the list.  Something like this.

Dictionary<string, int> d = new Dictionary<string, int>() { { "A", 4 }, { "B", 1 }, { "C", 5 }, { "D", 2 } };

Would someone please provide an example of a way to do this using lambda expressions.  It seems like it should be pretty simple, but this one has me stumped.  Thanks!

Answer 1

var dictionary = list.GroupBy(str => str)
    .ToDictionary(group => group.Key, group => group.Count());

Answer 2

Thanks!  Proper use of "GroupBy" always confuses me.