using System;

using System.Collections.Generic;

using System.Data;

​

using System.Linq;

using System.Threading;

using System.Threading.Tasks;

using System.Net;

using System.Web;

​

public class Program

{

    public static void Main()

    {

        var path = "fd1/fd2/file.txt";

        var splits = path.Split('/');

        var res = splits.Slice(0, 2);

        var str = res.Aggregate("", (cur, it) => $"{cur} {it}");

        Console.WriteLine($"res: {str}");

        Console.WriteLine($"slice {splits.Last()}");

    }

}

​

​

public static class Extensions

{

    /// <summary>

    /// Get the string slice between the two indexes.

    /// Inclusive for start index, exclusive for end index.

    /// </summary>

    public static string Slice(this string source, int start, int end)

    {

        if (end < 0) // Keep this for negative end support

        {

            end = source.Length + end;

        }

        int len = end - start;               // Calculate length

        return source.Substring(start, len); // Return Substring of length

    }

​

​

    public static IEnumerable<T> Slice<T>(this T[] source, int start, int end)

    {

        if (end < 0) // Keep this for negative end support

        {

            end = source.Length + end;

        }

        int len = end - start;               // Calculate length

                                             //return source.Substring(start, len); // Return Substring of length

        var res = new List<T>();

        for (int i = start; i <= end; i++)

        {

            var it = source[i];

            res.Add(it);

        }

        return res;

    }

​

}