Nothing vs String.Empty
Hi, I'm using VB 2005, WinForms. I have a question about initializing variables and setting their value from a best practices point of view.
Let say I have a String variable called "strMyString" and I want to initialize its value to "No Value".
What is the best way to accomplish this, so that I can avoid problems in my code with DBNulls later at runtime.
Which of the following would be better -- or does it make a difference.
Dim strMyString as String = Nothing
or
Dim strMyString as String = String.Empty
or
Dim strMyString as String = ""
Is there a better way?
Thanks for your help,
Fulano
Let say I have a String variable called "strMyString" and I want to initialize its value to "No Value".
What is the best way to accomplish this, so that I can avoid problems in my code with DBNulls later at runtime.
Which of the following would be better -- or does it make a difference.
Dim strMyString as String = Nothing
or
Dim strMyString as String = String.Empty
or
Dim strMyString as String = ""
Is there a better way?
Thanks for your help,
Fulano
ASKER
Hi JPaulino, nice to hear from you...
Interesting...I didn't know that Nothing was limited to Objects. It works for Strings, but lately I've begun to get a little worried that I'm using it too often.
Thanks for the input!
Fulano
Interesting...I didn't know that Nothing was limited to Objects. It works for Strings, but lately I've begun to get a little worried that I'm using it too often.
Thanks for the input!
Fulano
Indeed a string can be Nothing because it is a reference type.
I think the best equivalence to DbNull is Nothing.
String.Empty is a string that is empty (zero-length) but it is not Nothing
I think the best equivalence to DbNull is Nothing.
String.Empty is a string that is empty (zero-length) but it is not Nothing
to elaborate a bit more, it is not the same:
UPDATE SOMETABLE SET SOMEFIELD = '' (can be represented by String.Empty)
than
UPDATE SOMETABLE SET SOMEFIELD = NULL (can be represented by Nothing)
UPDATE SOMETABLE SET SOMEFIELD = '' (can be represented by String.Empty)
than
UPDATE SOMETABLE SET SOMEFIELD = NULL (can be represented by Nothing)
ASKER
Hi Jaime,
OK, so let me see if I understand your perspective. -- Are you saying that it is better to use Nothing to avoid a DBNull, or that if you use Nothing, you almost guarantee yourself a DBNull?
Thanks,
Fulano
OK, so let me see if I understand your perspective. -- Are you saying that it is better to use Nothing to avoid a DBNull, or that if you use Nothing, you almost guarantee yourself a DBNull?
Thanks,
Fulano
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also consider this:
Dim value as DbNull
Dim myString as String = value.ToString() ' will return you an empty (not null) string
Dim value as DbNull
Dim myString as String = value.ToString() ' will return you an empty (not null) string
ASKER
All very good advice and I learn a few things along the way. I thank you all for your suggestions and believe that a split of the points is equitable, given all the on-point suggestions made.
Thanks,
Fulano
Thanks,
Fulano
String.Empty or "" is the same but you type " " (with a space in the middle) and cause you problems. Nothing is used for objects and not string.
I always use String.Empty