Question

List has object which has properties as follows :

public class PropertyDetails
{

 public int Sequence { get; set; }

 public int Length { get; set; }

 public string Type { get; set; }

 public int Index { get; set; }

}

List will have sorted Sequence .

List has object values as follows:

Sequence= 1 Length=20 Type=”” Index=0

Sequence= 2 Length=8 Type=”” Index=0

Sequence= 3 Length=6 Type=”” Index=0

Sequence= 4 Length=20 Type=”” Index=0

Sequence= 5 Length=8 Type=”” Index=0

I want Linq query which will give me result List as

Sequence= 1 Length=20Type=”” Index=20

Sequence= 2 Length=8 Type=”” Index=28

Sequence= 3 Length=6 Type=”” Index=34

Sequence= 4 Length=20 Type=”” Index=54

Sequence= 5 Length=8 Type=”” Index=62

Where index is cumulative sum of Length considering sequence.

Answer 1

I never though I’d say this, but I find Jon’s solution to be overengineering. Rather, I find LINQ to be the wrong solution for this problem. You want to manipulate state, not a good fit for traditional LINQ-operators.

I’d just do this:

var sum = 0;
foreach (var p in list) {
  sum += p.Length;
  p.Index = sum;
}

LINQ is a hammer. Make sure you use the right tool for the problem, instead of just asking for hammering-advice.