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Null

Null
is a symbol used to indicate the absence of an expression or a result. It is not displayed in ordinary output.

When Null appears as a complete output expression, no output is printed.
  • 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.
When a sequence of commands ends with a semicolon, no output is shown:
The full form of the output is Null:
If you forget a semicolon in a program you may see output with Null in it:
This is because the whitespace is interpreted as multiplication. Redefine with a semicolon:
When a sequence of commands ends with a semicolon, no output is shown:
In[1]:=
Click for copyable input
The full form of the output is Null:
In[2]:=
Click for copyable input
Out[2]//FullForm=
 
If you forget a semicolon in a program you may see output with Null in it:
In[1]:=
Click for copyable input
In[2]:=
Click for copyable input
Out[2]=
This is because the whitespace is interpreted as multiplication. Redefine with a semicolon:
In[3]:=
Click for copyable input
In[4]:=
Click for copyable input
Out[4]=
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