group List<T> and create new list with count

Question

I have next class and list:

public class cls1
{
  public string prop1 {get; set;}
  public string prop2 {get; set;}
  public string prop3 {get; set;}
}

public List<cls1> list = new List(cls1)();

I need to group list by prop2 field and count this field and on the end order it descending by count.

Answer 1

You can do:

var query = list.GroupBy(r => r.prop2)
                .Select(grp => new
                {
                    Key = grp.Key,
                    Count = grp.Count(),
                })
                .OrderByDescending(r => r.Count);