note 121995 added to language.types.null

NULL is supposed to indicate the absence of a value, rather than being thought of as a value itself. It's the empty slot, it's the missing information, it's the unanswered question. It's not a jumped-up zero or empty set. This is why a variable containing a NULL is considered to be unset: it doesn't have a value. Setting a variable to NULL is telling it to forget its value without providing a replacement value to remember instead. The variable remains so that you can give it a proper value to remember later; this is especially important when the variable is an array element or object property. It's a bit of semantic awkwardness to speak of a "null value", but if a variable can exist without having a value, the language and implementation have to have something to represent that situation. Because someone will ask. If only to see if the slot has been filled. ---- Server IP: 150.242.41.218 Probable Submitter: 222.153.170.187 ---- Manual Page -- http://php.net/manual/en/language.types.null.php Edit -- https://master.php.net/note/edit/121995 Del: integrated -- https://master.php.net/note/delete/121995/integrated Del: useless -- https://master.php.net/note/delete/121995/useless Del: bad code -- https://master.php.net/note/delete/121995/bad+code Del: spam -- https://master.php.net/note/delete/121995/spam Del: non-english -- https://master.php.net/note/delete/121995/non-english Del: in docs -- https://master.php.net/note/delete/121995/in+docs Del: other reasons-- https://master.php.net/note/delete/121995 Reject -- https://master.php.net/note/reject/121995 Search -- https://master.php.net/manage/user-notes.php