By: chippy088

chippy088 — Mon, 22 Nov 2010 11:38:25 +0000

Just for information only, don’t know if it will help with Java, but, NULL is also used within a batch file. It is actually defined in the OS as a virtual device, I like to think of it as a black hole. Anything written to it is swallowed up and never to be retrieved.

I have used it, in batch files,when a calling a command, which returns a status value/error code to the calling prog, and I have not wanted it to be displayed on screen. It is a pointer to a ‘void’, so the return value/error code gets dropped.

Your ‘emty string(” ” )’ actually isn’t empty, it contains a space (chr$32) and empty string is indicated by “” (no space between the quotes.) so if you are having problems with empty strings, this may be the reason.

I am not conversant with java, but in C, C++, VB (and many other high level languages,) it is an indication that the variable hasn’t been used, (but it has been declared, and a pointer has been allocated for any value it recieves) or, it has been emptied, so it can be re-used as a clean container.

By: tomliotta

tomliotta — Fri, 19 Nov 2010 03:22:34 +0000

wat is the meaning of the abouve if statement?

(name == null) says that no assignment has been made yet.
(name == “”) says that an assignment has been made; its value is “”.

Tom

By: carlosdl

carlosdl — Thu, 18 Nov 2010 15:15:42 +0000

The question is not related to databases at all, but the answer might still help. You might want to take a look at this: null : Java Glossary Experimenting is usually a good way to learn.

Comments on: null v/s ” “(empty string) in Java

By: chippy088

By: tomliotta

By: carlosdl