How do I get the index of the highest value in an array using LINQ?

Question

I have an array of doubles and I want the index of the highest value. These are the solutions that I\'ve come up with so far but I think that there must be a more elegant so

Answer 1

Meh, why make it overcomplicated? This is the simplest way.

var indexAtMax = scores.ToList().IndexOf(scores.Max());

Yeah, you could make an extension method to use less memory, but unless you're dealing with huge arrays, you will never notice the difference.

Answer 2

This isn't the only Aggregate based solution, but this is really just a single line solution.

double[] score = new double[] { 12.2, 13.3, 5, 17.2, 2.2, 4.5 };

var max = score.Select((val,ix)=>new{val,ix}).Aggregate(new{val=-1.0,ix=-1},(z,last)=>z.val>last.val?z:last);

Console.WriteLine ("maximum value is {0}", max.val );
Console.WriteLine ("index of maximum value is {0}", max.ix );

Answer 3

Try this one which is completely LINQ and has the best performance:

var indexAtMax = scores.Select((x, i) => new { x, i })
            .Aggregate((a, a1) => a.x > a1.x ? a : a1).i;