Stackoverflow error when compiling code in C#

Question

I am doing an exercise in C# and I am not able to find the error in my code, because I have already checked the resolution of the problem and I can’t find the difference in the syntax of the code that is causing the error.

I’m getting the following feedback on the console:

Process is terminating due to Stackoverflowexception.

Follow below the codes:

Program.Cs

using System;
using Course.Entities;

namespace Course
{
    class Program
    {
        static void Main(string[] args)
        {
            Comment c1 = new Comment("Have a nice trip!");
            Comment c2 = new Comment("Wow that's awesome!");
            Post p1 = new Post(
                DateTime.Parse("21/06/2018 13:05:44"),
                "Travelling to New Zealand",
                "I'm going to visit this wonderful country!",
                12);
            p1.AddComment(c1);
            p1.AddComment(c2);

            Comment c3 = new Comment("Good night");
            Comment c4 = new Comment("May the force be with you");
            Post p2 = new Post(
                DateTime.Parse("28/07/2018 23:14:19"),
                "Good night guys",
                "See you tomorrow",
                5);
            p2.AddComment(c3);
            p2.AddComment(c4);

            Console.WriteLine(p1);
            Console.WriteLine(p2);
        }
    }
}

Comment.Cs

namespace Course.Entities
{
    class Comment
    {
        public string Text { get; set; }

        public Comment()
        {

        }

        public Comment(string text)
        {
            Text = text;
        }
    }
}

Post.Cs

    using System;
    using System.Collections.Generic;
    using System.Text;

    namespace Course.Entities
    {
        class Post
        {
            public DateTime Moment { get; set; }
            public string Title { get; set; }
            public string Content { get; set; }
            public int Likes { get; set; }
            public List<Comment> Comments { get; set; } = new List<Comment>();

            public Post()
            {

            }

            public Post(DateTime moment, string title, string content, int likes)
            {
                Moment = moment;
                Title = title;
                Content = content;
                Likes = likes;
            }

            public void AddComment(Comment comment)
            {
                Comments.Add(comment);
            }
            public void RemoveComment(Comment comment)
            {
                Comments.Remove(comment);
            }

            public override string ToString()
            {
                StringBuilder sb = new StringBuilder();
                sb.AppendLine(Title);
                sb.Append(Likes);
                sb.Append(" Likes - ");
                sb.AppendLine(Moment.ToString("dd/MM/yyyy HH:mm:ss"));
                sb.AppendLine(Content);
                sb.AppendLine("Comments:");
                foreach (Comment c in Comments)
                {
                    sb.AppendLine(c.Text);
                }
                return ToString();
            }
        }

}

Answer 1

The problem is the ToString(). Ali is calling himself at the time of returning something, then enters into infinite loop and breaks. I think you forgot to use the text object there, it would be something like this:

return sb.ToString();

This use of ToString() is wrong and abusive.

I think I could improve some things, for example allow the builder to accept the comments. But that’s something to think about. I don’t know if I could avoid that StringBuilder.

I gave a modernized and simplified (I find it easier to read) and was like this:

using System;
using static System.Console;
using System.Collections.Generic;
using System.Text;

class Program {
    static void Main() {
        var p1 = new Post(DateTime.Now, "Travelling to New Zealand", "I'm going to visit this wonderful country!", 12);
        p1.AddComment(new Comment("Have a nice trip!"));
        p1.AddComment(new Comment("Wow that's awesome!"));
        var p2 = new Post(DateTime.Now, "Good night guys",  "See you tomorrow", 5);
        p2.AddComment(new Comment("Good night"));
        p2.AddComment(new Comment("May the force be with you"));
        WriteLine(p1);
        WriteLine(p2);
    }
}

class Comment {
    public string Text { get; set; }
    public Comment() {}
    public Comment(string text) => Text = text;
}
class Post {
    public DateTime Moment { get; set; }
    public string Title { get; set; }
    public string Content { get; set; }
    public int Likes { get; set; }
    public List<Comment> Comments { get; set; } = new List<Comment>();
    public Post() {}
    public Post(DateTime moment, string title, string content, int likes) {
        Moment = moment;
        Title = title;
        Content = content;
        Likes = likes;
    }
    public void AddComment(Comment comment) => Comments.Add(comment);
    public void RemoveComment(Comment comment) => Comments.Remove(comment);
    public override string ToString() {
        var sb = new StringBuilder();
        sb.AppendLine(Title);
        sb.Append(Likes);
        sb.Append(" Likes - ");
        sb.AppendLine(Moment.ToString("dd/MM/yyyy HH:mm:ss"));
        sb.AppendLine(Content);
        sb.AppendLine("Comments:");
        foreach (Comment c in Comments) sb.AppendLine(c.Text);
        return sb.ToString();
    }
}

Behold working in the ideone. And in the .NET Fiddle. Also put on the Github for future reference.