Anyone who has programmed for any length of time has encountered the concepts of null and empty strings. They are not the same, and confusing the two can cause some serious problems. This article deals with these concepts in the context of PHP and MySQL.

They start with a bit of a quiz before getting into how to handle them correctly - making null "safe" and working with it correctly in a MySQL context. SQL statements and table structures are included for their examples.

As of PHP 5.2.1, json_decode() no longer follows the published standards for JSON-encoded texts. Why not? For no reason other than the convenience of those ignorant of JSON standards.

His complaint stems from the results of a vat_dump statement - prior to this version it would give a NULL, but now it returns a "bool(true)" value back, resulting in some breakage of previous scripts. He spends the rest of the post explaining his voyage through the JSON world and how things are supposed to behave. He also digs a little deeper into the var_dump issue and why he thinks it's such a bad thing.