Null
is a symbol used to indicate the absence of an expression or a result. When it appears as a complete output expression, no output is printed.
Details
- e1;e2;…;ek; returns Null, and prints no output.
- Expressions like f[e1,,e2] are interpreted to have Null between each pair of adjacent commas.
- Null represents the absence of content or elements in such constructs as InputField or Grid.
Examples
Basic Examples (2)
When a sequence of commands ends with a semicolon, no output is shown:
null = (a = 1 + 2;b = a + 3;)The full form of the output is Null:
FullForm[null]If you forget a semicolon in a program you may see output with Null in it:
f[x_] := Module[{y = x},
While[y > 2, y = Sqrt[y]]
y
]f[100.]This is because the whitespace is interpreted as multiplication. Redefine with a semicolon:
f[x_] := Module[{y = x},
While[y > 2, y = Sqrt[y]];
y
]f[100.]Text
Wolfram Research (1988), Null, Wolfram Language function, https://reference.wolfram.com/language/ref/Null.html (updated 2007).
CMS
Wolfram Language. 1988. "Null." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2007. https://reference.wolfram.com/language/ref/Null.html.
APA
Wolfram Language. (1988). Null. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Null.html