max date record in LINQ

To get the maximum Sample value by date without having to sort (which is not really necessary to just get the maximum):

var maxSample  = Samples.Where(s => s.Date == Samples.Max(x => x.Date))
                        .FirstOrDefault();

Starting from .NET 6 MaxBy LINQ method is available.

var result = items.MaxBy(i => i.Date);

Prior to .NET 6:

O(n log n):

var result = items.OrderByDescending(i => i.Date).First();

O(n) – but iterates over the sequence twice:

var max = items.Max(i => i.Date);
var result = items.First(i => i.Date == max);

Or you can use MoreLINQ which has MaxBy method which is O(n)

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