.NET SqlDataReader Item[] vs. GetString(GetOrdinal())?

Question

Using the SqlDataReader class, what, if any, are the functional differences between:

(string) dataReader[\"MyFieldName\"];

and

Answer 1

//Well, we want to avoid the null exception issue entirely.
//Let's check for null first, before we try to use the value.

if( !dataReader.IsDBNull(dataReader.GetOrdinal("MyFieldName")))
{
//Store my data or use the value
string mystring=dataReader.GetString(dataReader.GetOrdinal("MyFieldName"));
}

Serendipity is a wonderful discovery method.