Collection Performance: Finding First or Last and Count

When you need to find the first or last item in a collection or obtain its count, many developers use the LINQ methods First(), Last(), or Count() as shown in this example:

var person = personCollection.First();
var person = personCollection.Last();
var count = personCollection.Count();

Another alternative for obtaining the same information without LINQ could be achieved like this:

var person = personCollection[0];
var person = personCollection[personCollection.Count - 1];
var count = personCollection.Count

Using LINQ is more readable, but is it more performant?

Benchmark Results

The straightforward answer is that using LINQ is generally three times less performant. If your code heavily depends on LINQ methods, I recommend refactoring it.

When I setup my EditorConfig to check for these issues, it looks like this: dotnet_diagnostic.CA1826.severity = error

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