Hi Elena,

You shouldn't worry about the message you received from the compiler at line 44, it's just telling you that you don't need to use ToString() in this case, as it is clear for the compiler that you are expecting a string output from the given object (whereas in foreach-loops it is required to use ToString() on a given object).

I have also added a default constructor in your Article class which allows you to directly set the default values when creating a new Article object.

However, there was a problem with your split() function, which led to wrong results and that had to be changed from Console.ReadLine().Split(", ".ToCharArray()).ToArray(); => Console.ReadLine().Split(", ", StringSplitOptions.RemoveEmptyEntries).ToArray();

ToCharArray should be used in the following context :

string someLine = "Hello World";

char[] array = someLine.ToCharArray() ;

New code(100%):

using System;
using System.Linq;
using System.Collections.Generic;

namespace ObjectsAndClasses
{
    class MainClass
    {
        public static void Main()
        {
            //string someLine = "Hello World";
            //char[] array = someLine.ToCharArray();

            string[] input = Console.ReadLine()
                .Split(", ", StringSplitOptions.RemoveEmptyEntries)
                .ToArray();

            int n = int.Parse(Console.ReadLine());

            Article article = new Article(input[0], input[1], input[2]);

            //article.Title = input[0];
            //article.Content = input[1];
            //article.Author = input[2];

            for (int i = 0; i < n; i++)
            {
                string[] command = Console.ReadLine()
                    .Split(": ", StringSplitOptions.RemoveEmptyEntries)
                    .ToArray();

                if (command[0] == "Edit")
                {
                    article.Edit(command[1]);
                }

                else if (command[0] == "ChangeAuthor")
                {
                    article.ChangeAuthor(command[1]);
                }

                else if (command[0] == "Rename")
                {
                    article.Rename(command[1]);
                }
            }

            Console.WriteLine(article.ToString());
        }

        public class Article
        {
            public Article(string title, string content, string author)
            {
                this.Title = title;
                this.Content = content;
                this.Author = author;
            }

            public object Title { get; set; }

            public object Content { get; set; }

            public object Author { get; set; }

            public void Edit(string newContent)
            {
                this.Content = newContent;
            }

            public void ChangeAuthor(string newAuthor)
            {
                this.Author = newAuthor;
            }

            public void Rename(string newTitle)
            {
                this.Title = newTitle;
            }

            public override string ToString()
            {
                return $"{this.Title} - {this.Content}: {this.Author}";
            }
        }
    }
}
 

Какъв е смисъла да кастваш командата към масив от чарове след като после и казваш ToArray();

 string[] command = Console.ReadLine().Split(": ".ToCharArray()).ToArray();