Question

Is there a difference between NULL and null in PHP? Sometimes they seem to be interchangeable and sometimes not.

edit: for some reason when I read the documentation linked to in the answer (before posting this question) I read it as ‘case sensitive’ instead of ‘case insensitive’ which was the whole reason I posted this question in the first place…

Answer 1

Null is case insensitive.

From the documentation:

There is only one value of type null, and that is the case-insensitive keyword NULL.