Question

Hi I have a lookup type that stores strings and ints.

static Lookup<string, int> lookup;
lookup = (Lookup<string, int>)list.ToLookup(i => i.IP, i => i.Number);

But now I need to sort this lookup by the values (number), and get the top 10 keys with their values.

How is this possible?

Answer 1

I’m not sure why you are casting a Lookup<string, int> to a Lookup<string, string>, but the general answer you want is:

var list = new List<Test>
    {
            new Test { IP = "A", Number = 1 }, new Test { IP = "A", Number = 3 }, new Test { IP = "A", Number = 4 },
            new Test { IP = "B", Number = 1 }, new Test { IP = "B", Number = 1 }, new Test { IP = "B", Number = 1 },
            new Test { IP = "C", Number = 1 },
            new Test { IP = "D", Number = 1 },
            new Test { IP = "E", Number = 1 }, new Test { IP = "E", Number = 1 }, new Test { IP = "E", Number = 1 }
    };

var values = list.ToLookup(s => s.IP, s => s.Number)
                 .OrderByDescending(s => s.Count())
                 .Take(10);