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KeySelect[assoc,crit]

selects elements in the association assoc for which crit applied to their keys is True.

KeySelect[crit]

represents an operator form of KeySelect that can be applied to an expression.

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KeySelect

KeySelect[assoc,crit]

selects elements in the association assoc for which crit applied to their keys is True.

KeySelect[crit]

represents an operator form of KeySelect that can be applied to an expression.

Details

Examples

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Basic Examples  (3)

Select entries with odd keys:

Wolfram Language code: KeySelect[<|1 -> a, 2 -> b, 3 -> c|>, OddQ]

Select entries from an association, using another association as a criterion:

Wolfram Language code: KeySelect[<|1 -> a, 2 -> b, 3 -> c|>, <|1 -> False, 2 -> True, 3 -> True|>]

Use the operator form of KeySelect:

Wolfram Language code: KeySelect[OddQ][<|1 -> 2, 2 -> 3, 3 -> 4|>]

Properties & Relations  (1)

Compute KeySelect in parallel:

Wolfram Language code: Parallelize[KeySelect[AssociationMap[Identity, Range[100]], PrimeQ]]
Wolfram Research (2014), KeySelect, Wolfram Language function, https://reference.wolfram.com/language/ref/KeySelect.html.

Text

Wolfram Research (2014), KeySelect, Wolfram Language function, https://reference.wolfram.com/language/ref/KeySelect.html.

CMS

Wolfram Language. 2014. "KeySelect." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/KeySelect.html.

APA

Wolfram Language. (2014). KeySelect. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/KeySelect.html

BibTeX

@misc{reference.wolfram_2026_keyselect, author="Wolfram Research", title="{KeySelect}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/KeySelect.html}", note=[Accessed: 13-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_keyselect, organization={Wolfram Research}, title={KeySelect}, year={2014}, url={https://reference.wolfram.com/language/ref/KeySelect.html}, note=[Accessed: 13-June-2026]}