Removing extra commas from string after using String.Join to convert array to string (C#)

Question

I\'m converting an array into a string using String.Join. A small issue I have is that, in the array some index positions will be blank. An example is below:

Answer 1

Extension method:

public static string ToStringWithoutExtraCommas(this object[] array)
{
    StringBuilder sb = new StringBuilder();
    foreach (object o in array)
    {

        if ((o is string && !string.IsNullOrEmpty((string)o)) || o != null)
            sb.Append(o.ToString()).Append(",");
    }

    sb.Remove(sb.Length - 1, 1);

    return sb.ToString();
}