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Null may refer to:

Science, technology, and mathematics

Astronomy

Nuller, an optical tool using interferometry to block certain sources of light

Computing

Null (SQL) (or NULL), a special marker and keyword in SQL indicating that a data value does not exist, is not known, or is missing.
Null character, the zero-valued ASCII character, also designated by NUL, often used as a terminator, separator or filler. This symbol has no visual representation.
Null device, a virtual file that discards data written to it, on Unix systems /dev/null
Null pointer or reference (sometimes written NULL, nil, or None), an object pointer (or reference) not currently set to point (or refer) to a valid object

Mathematics

Null (mathematics), a zero value in several branches of mathematics

Physics

Null (physics), a point in a field where the field quantity is zero
Null (radio), a concept in electromagnetism

Arts and media

The Null Corporation, an imprint of the band Nine Inch Nails
Null (Intronaut EP), 2006
Null (Foetus EP), 1995
Null, an identity of the character Gray Fox in the Metal Gear Solid: Portable Ops video game
Null, a villain from Teenage Mutant Ninja Turtles Adventures
Null (The Legend of Zelda), the main antagonist of The Legend of Zelda: Echoes of Wisdom
Null, a mysterious character from Baldi's Basics.

People with the surname

Ashley Null, American Anglican theologian
Christopher Null (born 1971), American writer and film critic
Eduard van der Nüll (1812–1868), Austrian architect
Gary Null (born 1945), American radio host and author of works about alternative medicine
Keith Null (born 1985), American football player
Luke Null (born 1990), American actor and comedian

@@ Line 1: / Line 1: @@
+{{wiktionary|Null|null|a-null|núll|Nullus}}
-'''''Null''''' is a term used, often in [[computer science]], to signify [[nothing]]ness.
+'''Null''' may refer to:
+{{TOC right}}
+==Science, technology, and mathematics==
-In [[computer programming]], null is a special value for a [[pointer]] (or [[reference]]) that is used to signify that the pointer's target is not a valid data element.  Often, 0 (zero) is used as the null value, as most [[operating system]]s consider it an error to try to access such a low memory address. Null is used in many other disciplines, and is not just used for pointers in programming. (Example: /dev/null, a [[virtual device]] on [[UNIX]] systems that does nothing with its input and produces no output)
+===Astronomy===
+*[[Nuller]], an optical tool using interferometry to block certain sources of light
+===Computing===
+*[[Null (SQL)]] (or NULL), a special marker and keyword in SQL indicating that a data value does not exist, is not known, or is missing.
+*[[Null character]], the zero-valued ASCII character, also designated by {{mono|NUL}}, often used as a terminator, separator or filler. This symbol has no visual representation.
+*[[Null device]], a virtual file that discards data written to it, on Unix systems <code>/dev/null</code>
+*[[Null pointer]] or reference (sometimes written <code>NULL</code>, <code>nil</code>, or <code>None</code>), an object pointer (or reference) not currently set to point (or refer) to a valid object
+===Mathematics===
-The [[ASCII]] character code with code value 0 is called a '''null character''', sometimes denoted as NUL. Also, [[Unicode]] character 0000 is Null, denoted, like ASCII convention, as NUL.
+*[[Null (mathematics)]], a zero value in several branches of mathematics
+===Physics===
-In some languages, such as [[Lisp programming language|LISP]], the designation is called '''nil'''.
+*[[Null (physics)]], a point in a field where the field quantity is zero
+*[[Null (radio)]], a concept in electromagnetism
+==Arts and media==
-In many disciplines, the concept of null allows a [[Many-valued logic|three-valued logic]], with null indicating 'unknown'.
+*The Null Corporation, an imprint of the band [[Nine Inch Nails]]
+*[[Null (Intronaut EP)|''Null'' (Intronaut EP)]], 2006
+*[[Null (Foetus EP)|''Null'' (Foetus EP)]], 1995
+*Null, an identity of the character [[Gray Fox (Metal Gear)|Gray Fox]] in the ''Metal Gear Solid: Portable Ops'' video game
+*Null, a villain from ''[[Teenage Mutant Ninja Turtles Adventures]]''
+*[[Null (The Legend of Zelda)|Null (''The Legend of Zelda'')]], the main antagonist of ''The Legend of Zelda: Echoes of Wisdom''
+*Null, a mysterious character from [[Baldi's Basics in Education and Learning|Baldi's Basics]].
+==People with the surname==
-Note that this is not the same as the definition of [[nothing]] because it is more related to computer science.
+*[[Ashley Null]], American Anglican theologian
+*[[Christopher Null]] (born 1971), American writer and film critic
+*[[Eduard van der Nüll]] (1812–1868), Austrian architect
+*[[Gary Null]] (born 1945), American radio host and author of works about alternative medicine
+*[[Keith Null]] (born 1985), American football player
+*[[Luke Null]] (born 1990), American actor and comedian
-See also: [[null set]].
+==See also==
+*[[Ø (disambiguation)]]
+*[[Null symbol (disambiguation)]]
+*[[0 (disambiguation)]]
+*[[Nil (disambiguation)]]
+*[[Nul (disambiguation)]]
+*[[Nullity (disambiguation)|Nullity]]
+*[[Nullification (disambiguation)|Nullification]]
+*[[Nothing (disambiguation)]]
+{{srt}}
+{{Disambiguation|surname}}
-----
-In [[radio]] [[electronics]], a '''null''' is an area or [[vector]] at which the [[signal]] from two or more of the [[antenna element]]s in an [[antenna system]] cancels out almost entirely.
-This can be an advantage, as nulls in the [[horizontal plane]] can be used to protect other transmitters from interference.  If not carefully planned however, nulls can affect the receivability of a [[signal]] in any given place.  [[Null fill]] in the [[vertical plane]] is used to prevent this.