Ranking items in a list with linq

Rich

14y19.2kLINQ

I am trying to figure out a way to rank items in a list, and hold the results in an object or another list. I know about the orderby method, but I don't exactly know how to go about creating a corresponding rank number for each item. Is this possible with linq? For example:

List numbers = new List();

numbers.Add(650);
numbers.Add(150);
numbers.Add(500);
numbers.Add(200);

and then store the results from either low to high or high to low here:

public class NumberRank
{
public int Number {get; set;}
public int Rank {get; set;}

public NumberRank(int number)
{
          Number = number;
          Rank = ????????;
        }
}

Thanks, in advance.

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes14y ago
Accepted answer
This should do it:

using System;
using System.Collections.Generic;
using System.Linq;

public class NumberRank
{
public int Number {get; set;}
public int Rank {get; set;}

public NumberRank(int number, int rank)
{
Number = number;
Rank = rank;
}
}

class Test
{
static void Main()
{
List numbers = new List();

numbers.Add(650);
numbers.Add(150);
numbers.Add(500);
numbers.Add(200);

List numberRanks = numbers.OrderByDescending(n => n).Select((n, i) => new NumberRank(n, i + 1)).ToList();

// check it worked
foreach(NumberRank nr in numberRanks) Console.WriteLine("{0} : {1}", nr.Rank, nr.Number);
Console.ReadKey();
}
}

To rank in ascending order (i.e. lowest number first), then just replace OrderByDescending by OrderBy.
0
Rich14y ago
4 words, you are the man! Worked perfectly. That is a very clever. Once again, appreciate your time. I am learning so much. The more I learn the more excited I become. Thanks.
0