Note that NIL in most Lisps (Common Lisp in particular) is both a symbol and a list. It is not, contra the introduction to the Null pointer, an invalid object, it is the empty list (as well as the equivalent of false in Common Lisp, but not, say, Scheme). As the article does mention, NIL is first class, and the user can (though it is considered bad programming practice) create properties on NIL, as they can for any other symbol. Gorbag42 (talk) 16:55, 28 January 2024 (UTC)
A paragraph in the article contrasts a null pointer with a null in a relational database null. It describes the database null as an unknown value, but the Null (SQL) article says a database null is a non-existent value. So I've removed the whole paragraph.--A bit iffy (talk) 19:40, 20 April 2017 (UTC)
The section C currently says:
"dereferencing the null pointer is a perfectly valid but typically unwanted action that may lead to undefined but non-crashing behavior in the application"
But the section "Dereferencing" currently says:
"In C, the behavior of dereferencing a null pointer is undefined"
These statements are not the same. I think the problem is in the first one, because it seems to assume that the "null pointer" is the same as the pointer to address zero. But I'm no expert, so I thought the proper action is to put it here.. — Preceding unsigned comment added by 185.147.13.130 (talk) 15:01, 7 May 2018 (UTC)
<code>your code here </code>
next time you want to put code somewhere on Wikipedia. Please do not enter it into the article unless you find a citation for it. Holzklöppel (talk) 10:16, 20 August 2022 (UTC)The TenDRA compiler framework, which provides for architecture neutral representation of compiled programs, allows the user to set the null pointer representation to 0x55555555
. The representation helps find incorrect and non-portable programs.
I know the statements are correct. I don't know how to cite them since they are on GitHub at https://github.com/tendra/tendra/wiki/Talk:Null_pointer/About and https://github.com/tendra/tendra/blob/main/trans/man/trans.1/trans.1.xml#L1548.
Jeffrey Walton (talk) 16:01, 23 April 2023 (UTC)
"User code running in interpreted or virtual-machine languages generally does not suffer the problem of null pointer dereferencing." I have made the section on mitigation clearer. However, I left the sense of this in, but I think it is a dubious claim. Interpreted of VM languages may certainly have nulls. I think Java does. Ian.joyner (talk) 05:04, 26 August 2024 (UTC)