Extension method for StringComparison or any IComparer<string> that adds support for natural sorting (e.g. "abc1", "abc2", "abc10" instead of "abc1", "abc10", "abc2").

The library is written in C# and released with an MIT license, so feel free to fork or use commercially.

Any feedback is appreciated, please visit the issues page or send me an e-mail.

Binaries of the last build can be downloaded on the AppVeyor CI page of the project.

The library is also published on NuGet.org (prerelease), install using:

PM> Install-Package NaturalSort.Extension

^{NaturalSort.Extension is built for .NET v4.0 and .NET Standard 1.3.}

The recommended method for best results is to create the comparer by using the StringComparison enum.

var sequence = new[] { "img12.png", "img10.png", "img2.png", "img1.png" };
var ordered = sequence.OrderBy(x => x, StringComparison.OrdinalIgnoreCase.WithNaturalSort());
// ordered will be "img1.png", "img2.png", "img10.png", "img12.png"

For more information about natural sort order, see: Sorting for Humans: Natural Sort Order (Coding Horror).

The NaturalSortComparer created using the extension method is a IComparer<string>, which you can use in all the places that accept IComparer<string> (e.g. OrderBy, Array.Sort, ...)

If you wish, you can be more explicit by not using the .WithNaturalSort() extension method, and using the constructor directly:

new NaturalSortComparer(StringComparison.OrdinalIgnoreCase)

Note that if you are using a custom IComparer<string> (or StringComparer), you can also use that instead of the StringComparison enum. However, if you use StringComparison, it should perform better as it avoids constructing substrings.