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Unique

Unique

generates a new symbol, whose name is of the form $nnn.

generates a new symbol, with a name of the form x$nnn.

Unique[{x,y,…}]

generates a list of new symbols.

Unique["xxx"]

generates a new symbol, with a name of the form xxxnnn.

Details

Unique[x] numbers the symbols it creates using $ModuleNumber, and increments $ModuleNumber every time it is called.
Unique["xxx"] numbers the symbols it creates sequentially, starting at 1 for each string xxx.
Unique[name,{attr₁,attr₂,…}] generates a symbol that has the attributes attr_i.

Examples

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Basic Examples (2)

Create a unique symbol based on a name:

Wolfram Language code: Unique["x"]

Create a unique symbol based on an existing symbol:

Wolfram Language code: Unique[sym]

Scope (4)

Create a unique symbol with no particular name:

Wolfram Language code: Unique[]

Create a unique symbol whose name begins with x:

Wolfram Language code: Unique["x"]

Create several symbols at once:

Wolfram Language code: Unique[{"x", "y", "z"}]

Create a unique symbol in the way Module does:

Wolfram Language code: Unique[x, {Temporary}]

Compare with Module:

Wolfram Language code: Module[{x}, {x, Attributes[x]}]

Properties & Relations (2)

Each use of Unique[symbol] increments $ModuleNumber:

Wolfram Language code: {$ModuleNumber, Unique[x], $ModuleNumber}

Unique[symbol] creates symbols in the same way Module does:

Wolfram Language code: {Module[{x}, x], Unique[x]}

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