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MatchQ[expr,form]

returns True if expr matches the pattern form, and returns False otherwise.

MatchQ[form]

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

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MatchQ

MatchQ[expr,form]

returns True if expr matches the pattern form, and returns False otherwise.

MatchQ[form]

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

Details

Examples

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Basic Examples  (3)

Test if an expression is an integer:

Wolfram Language code: MatchQ[12345, _Integer]

Test if an expression is a sum of two or more terms:

Wolfram Language code: MatchQ[(x - 1)(1 + 2 x + 3 x ^ 2), Plus[_, __]]
Wolfram Language code: MatchQ[Expand[x(1 + 2 x + 3 x ^ 2)], Plus[_, __]]

Test if an expression is explicitly zero:

Wolfram Language code: MatchQ[1 + 1 / GoldenRatio - GoldenRatio, 0]
Wolfram Language code: MatchQ[Simplify[1 + 1 / GoldenRatio - GoldenRatio], 0]

Scope  (10)

Match an association:

Wolfram Language code: MatchQ[<|a -> 1, b -> 2|>, _Association]

Match a rule in an association, using an association as a pattern:

Wolfram Language code: MatchQ[<|a -> 1|>, <|a -> _|>]
Wolfram Language code: MatchQ[<|a -> 1|>, <|_ -> 1|>]

KeyValuePattern lets you match any element in an association:

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

It also works on lists of rules:

Wolfram Language code: MatchQ[{a -> 1, b -> 2, c -> 3}, KeyValuePattern[b -> 2]]

Match a rule in an association with a condition:

Wolfram Language code: MatchQ[<|a -> 1|>, <|a -> _ ? OddQ|>]
Wolfram Language code: MatchQ[<|a -> "foo"|>, <|a -> x_ /; StringQ[x]|>]

Match a Rule in an association using Alternatives:

Wolfram Language code: MatchQ[<|a -> 1|>, <|_ -> 1 | 2|>]

Use Verbatim to match a literal blank:

Wolfram Language code: MatchQ[<|a -> _|>, <|a -> Verbatim[_]|>]

_ or Blank has special meaning in an association used as a pattern:

Wolfram Language code: MatchQ[<|a -> 1|>, <|a -> _|>]

Use __ or BlankSequence to match more than one rule in an association:

Wolfram Language code: MatchQ[<|a -> 1, b -> 2|>, <|_|>]
Wolfram Language code: MatchQ[<|a -> 1, b -> 2|>, <|__|>]

Match an association containing a given rule and possibly more:

Wolfram Language code: MatchQ[<|a -> 1|>, <|a -> 1, ___|>]
Wolfram Language code: MatchQ[<|a -> 1, b -> 2|>, <|a -> 1, ___|>]

Match an association containing three elements:

Wolfram Language code: MatchQ[<|a -> 1, b -> 2, c -> 3|>, <|_, _, _|>]
Wolfram Language code: MatchQ[<|a -> 1, b -> 2, c -> 3|>, a_ /; Length[a] == 3]

Match nested associations:

Wolfram Language code: MatchQ[<|1 -> <|2 -> x|>|>, <|_ -> <|_|>|>]

Properties & Relations  (1)

Replace[expr,lhsrhs] returns a transformed result if and only if MatchQ[expr,lhs] yields True:

Wolfram Language code: {Replace[{1}, {x_Integer} :> 2x], MatchQ[{1}, {x_Integer}]}
Wolfram Language code: {Replace[{1}, x_Integer :> 2x], MatchQ[{1}, x_Integer]}
Wolfram Research (1988), MatchQ, Wolfram Language function, https://reference.wolfram.com/language/ref/MatchQ.html (updated 2014).

Text

Wolfram Research (1988), MatchQ, Wolfram Language function, https://reference.wolfram.com/language/ref/MatchQ.html (updated 2014).

CMS

Wolfram Language. 1988. "MatchQ." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 2014. https://reference.wolfram.com/language/ref/MatchQ.html.

APA

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

BibTeX

@misc{reference.wolfram_2026_matchq, author="Wolfram Research", title="{MatchQ}", year="2014", howpublished="\url{https://reference.wolfram.com/language/ref/MatchQ.html}", note=[Accessed: 12-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_matchq, organization={Wolfram Research}, title={MatchQ}, year={2014}, url={https://reference.wolfram.com/language/ref/MatchQ.html}, note=[Accessed: 12-June-2026]}