C# Extension Method for Object

Question

Is it a good idea to use an extension method on the Object class?

I was wondering if by registering this method if you were incurring a performance penalty as it would b

Answer 1

The following example demonstrates the extension method in use.

namespace NamespaceName
{
public static class CommonUtil
{
    public static string ListToString(this IList list)
    {
        StringBuilder result = new StringBuilder("");

        if (list.Count > 0)
        {
            result.Append(list[0].ToString());
            for (int i = 1; i < list.Count; i++)
                result.AppendFormat(", {0}", list[i].ToString());
        }
        return result.ToString();
    }
  }
}

The following example demonstrates how this method can be used.

var _list = DataContextORM.ExecuteQuery("Select name from products").ToList();
string result = _list.ListToString();