// C# Extension Method

// Doc: https://csharp-extension.com/en/method/1002107/string-extractdouble

​

// @nuget: Z.ExtensionMethods

​

using System;

using System.IO;

​

public class Program

{   

    public static void Main()

    {   

        string input = "Version 3.9";

​

        //C# Extension Method: String - ExtractDouble

        var output = input.ExtractDouble();

​

        Console.WriteLine(output);

    }

}