using System;

using System.Linq;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        double a=1000.045;

        Console.WriteLine(a.ToString(("#,0.00")));

        Console.WriteLine(Math.Round(a, 2));

        Console.WriteLine(Math.Round(a, 2, MidpointRounding.AwayFromZero));

        double b=0.85555;

        Console.WriteLine(b.ToString(("P")));

        int c= 123;

        Console.WriteLine(c.ToString(("d5")));

        string d="000789";

        Console.WriteLine(d.TrimStart('0'));

        string e = "a,b,c,d,e";

        Console.WriteLine(

            string.Join(",",e.Split(',').Select(x=>string.Format("'{0}'",x)))

        );

    }

}