Get the index of an element in a List that satisfies a condition

Question

Say I have a Point:

public class Point
{
    double X, Y;
}

I want to get the index of the element inside List<Point> that satisfy a condition, for example, with the maximum Point.X value inside List<Point>.

How would I do that with a LINQ expression?

score 6 · Answer 1 · answered Jul 09 '15 at 05:19

6

You can do using this Select() overlaod which takes index of item as well:

 var result = Points.Select((Point,Index)=> new { Index,Point})
                    .OrderByDescending(x=>x.Point.X).First().Index;

answered Jul 09 '15 at 05:19

Ehsan Sajjad

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cannot access the Index property. And why only `OrderByDescending` won't work here? – Amit Kumar Ghosh Jul 09 '15 at 05:33
@AmitKumarGhosh see https://dotnetfiddle.net/ZzuMyb – Ehsan Sajjad Jul 09 '15 at 06:06

Get the index of an element in a List that satisfies a condition

1 Answers1