Late to this party, but something I find useful wrt to NULL is that php's isset() will return FALSE if a variable is NULL. It would return TRUE if the same variable was set to 0 or empty string.
--Mike H PS sorry for the top post my blackberry is being a PITA ------Original Message------ From: [email protected] Sender: [email protected] To: NYPHP Talk ReplyTo: NYPHP Talk Subject: Re: [nyphp-talk] Need help understanding NULL Sent: Aug 30, 2009 10:12 AM Hans Zaunere wrote: > NULL is just a type - a type that can only ever be one thing - NULL I think I get that part now: The moment it has a known value, even if that value is '' or zero, then it's no longer NULL (at least in the world according to MySQL). > NULL comes from pointers, largely where there can be null references > or pointers. It's an address that doesn't point anywhere, but is > some way pointed to and acknowledged, thus it's not purely > non-existent (yes, we could argue for years on the subtle meanings of > NULL, void, undefined, etc. :) Hans, you're going to make my head explode. LOL > As always, there's only one real resource these days: > > http://en.wikipedia.org/wiki/Null Oddly, while I go to Wikipedia probably a dozen times a day for answers, it never occurred to me to look up NULL there. Go figure. > To me, pragmatically, NULL really only comes down to one thing - it's > a special type that always has a single value. Different languages > and environments then utilize this type differently, and add their > own meanings. Thus you need to read the different environment's docs > to learn how NULL is treated specifically in that environment, and > how it affects getting things down in that environment. There is no > "global" real meaning of NULL - it's language specific. Noted. > Other than that NULL is meaningless - it's NULL :) Bev :) _______________________________________________ New York PHP User Group Community Talk Mailing List http://lists.nyphp.org/mailman/listinfo/talk http://www.nyphp.org/show_participation.php Sent via BlackBerry from T-Mobile _______________________________________________ New York PHP User Group Community Talk Mailing List http://lists.nyphp.org/mailman/listinfo/talk http://www.nyphp.org/show_participation.php
