c# ((DateTime)object) vs Datetime.Parse

Question

I'm new to c#.

I've an SQLite table containing "marketDate" field (datatype Date) and I'm using SQLiteDataReader.

I need to build a string this way: MONDAY 2016-01-03

So far I've found 2 ways of doing it:

1)

myString = (DateTime.Parse(reader["marketDate"].ToString())).ToString("dddd").ToUpper() + " " + (DateTime.Parse(reader["marketDate"].ToString())).ToShortDateString();

2)

myString = ((DateTime)reader["marketDate"]).ToString("dddd").ToUpper() + " " + ((DateTime)reader["marketDate"]).ToShortDateString();

I'd like to know which is the best way of doing it (best practice), and I'd really appreciate if someone will explain me the differences beetween the 2 approaches datetime.parse and (datetime)object). I couldn't find any info about the second one.

Thanks

Answer 1

This:

DateTime.Parse(reader["marketDate"].ToString())

1. gets the date from the reader (reader["marketDate"]). The result is of type DateTime.

2. This DateTime is converted to a string (.ToString()).

3. This string is converted back to a DateTime (DateTime.Parse(...)).

As you can see, steps 2 and 3 are redundant and can be omitted. Which is exactly what your second code example does:

(DateTime)reader["marketDate"]

1. The date is read from the reader (reader["marketDate"]). This is currently of type DateTime, but the compiler does not know that yet (since reader's indexer returns the supertype object). Thus, we tell that compiler that we know this is a DateTime by explicitly casting it. This allows us to call DateTime-specific methods on it.

Since you asked about best practice: Your second example is better than the first one. However, my preferred solution would be to use SQLiteDataReader.GetDateTime:

reader.GetDateTime("marketDate")