Group list by month

Question

I have list with datetime objects. I would like to group by month and add it to the dictionary.

So after grouping process I want to have list per month and year. For e

Answer 1

Linq provides an option to convert your results into a dictionary:

myList.GroupBy(x => new {Month = x.myDate.Month, Year = x.myDate.Year})
      .ToDictionary(g => g.Key, g => g.Count())

Note that this will give you keys in form of {Month=1,Year=2015}. If you want a string instead, something like January 2015, you can use formatted date string as a key.