designPatternGuru/DesignPatternGuru/Builder/Products/Product.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Builder.Products
{
	internal class Product
	{
		private List<object> _parts = new List<object>();

		public void Add(string part)
		{
			_parts.Add(part);
		}

		public string ListParts()
		{
			StringBuilder sb = new StringBuilder();
			for (int i = 0; i < _parts.Count; i++)
			{
				sb.Append($"{_parts[i]}");
				if (i < _parts.Count - 1)
					sb.Append(", ");
			}

			return $"Product parts: {sb.ToString() + Environment.NewLine}";
		}
	}
}