C# String TrimEnd()

public string TrimEnd(params Char[] ch)

using System; 
        
    public class StringExample  
    {  
        public static void Main(string[] args)  
        {  
         string s1 = "Hello C#";
         char[] ch = {'#'};
         string s2 = s1.TrimEnd(ch);
         Console.WriteLine(s2);
         }  
    }  

Hello C