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Identity[expr]

gives expr (the identity operation).

Examples  
Basic Examples  
Applications  
Properties & Relations  
Neat Examples  
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Identity

Identity[expr]

gives expr (the identity operation).

Examples

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Basic Examples  (1)

Wolfram Language code: Identity[x + y]

Applications  (1)

Plot a collection of functions together with the line:

Wolfram Language code: Plot[Evaluate@Comap[{Identity, Exp, Log}, x], {x, -2, 2}, AspectRatio -> Automatic, PlotRange -> 2]

Properties & Relations  (4)

Identity is removed from functional composition:

Wolfram Language code: Composition[f, g, Identity, h, Identity]

The first derivative of the identity is the constant 1:

Wolfram Language code: Identity'

Sequence acts as a general identity for several arguments:

Wolfram Language code: {a, Sequence[b, c, d], e}

Identity as a pure function:

Wolfram Language code: #&[a]

Neat Examples  (1)

Tabulate square roots of values without using auxiliary variables:

Wolfram Language code: TableForm[Comap[{Identity, Sqrt}] /@ {0, 1.0, 2.0, 3.0, 4.0}]
Wolfram Research (1988), Identity, Wolfram Language function, https://reference.wolfram.com/language/ref/Identity.html.

Text

Wolfram Research (1988), Identity, Wolfram Language function, https://reference.wolfram.com/language/ref/Identity.html.

CMS

Wolfram Language. 1988. "Identity." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/Identity.html.

APA

Wolfram Language. (1988). Identity. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/Identity.html

BibTeX

@misc{reference.wolfram_2026_identity, author="Wolfram Research", title="{Identity}", year="1988", howpublished="\url{https://reference.wolfram.com/language/ref/Identity.html}", note=[Accessed: 13-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_identity, organization={Wolfram Research}, title={Identity}, year={1988}, url={https://reference.wolfram.com/language/ref/Identity.html}, note=[Accessed: 13-June-2026]}