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InexactNumberQ[expr]

returns True if expr is an inexact real or complex number, and returns False otherwise.

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InexactNumberQ

InexactNumberQ[expr]

returns True if expr is an inexact real or complex number, and returns False otherwise.

Details

Examples

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Basic Examples  (1)

InexactNumberQ tests whether an object is explicitly an inexact number:

Wolfram Language code: InexactNumberQ[5.6]
Wolfram Language code: InexactNumberQ[5 / 6]
Wolfram Language code: InexactNumberQ[x]

Scope  (2)

An approximate zero is inexact:

Wolfram Language code: z = N[Pi, 20] - (1299139324288/413528890451)
Wolfram Language code: InexactNumberQ[z]

Either real or imaginary parts of a complex number can be inexact:

Wolfram Language code: InexactNumberQ[1. + 2 I]
Wolfram Language code: InexactNumberQ[2 + N[Pi, 20] I]

If both real and imaginary parts are exact, then the number is not inexact:

Wolfram Language code: InexactNumberQ[3 + 4 / 5 I]

Properties & Relations  (4)

Numbers are considered either exact or approximate (inexact):

Wolfram Language code: numbers = {0, 1., 2`10, 3 / 4, 5 + 6 I, N[Pi, 7] + 8 I};
Wolfram Language code: TableForm[Table[{x, InexactNumberQ[x], ExactNumberQ[x]}, {x, numbers}], TableHeadings -> {{}, {"x", "inexact", "exact"}}]

Inexact numbers have Precision less than :

Wolfram Language code: numbers = {0, 1., 2`10, 3 / 4, 5 + 6 I, N[Pi, 7] + 8 I};
Wolfram Language code: TableForm[Table[{x, InexactNumberQ[x], Precision[x]}, {x, numbers}], TableHeadings -> {{}, {"x", "inexact", "Precision"}}]

Inexact numbers have head Real or Complex:

Wolfram Language code: numbers = {0, 1., 2`10, 3 / 4, 5 + 6 I, N[Pi, 7] + 8 I};
Wolfram Language code: TableForm[Table[{x, InexactNumberQ[x], Head[x]}, {x, numbers}], TableHeadings -> {{}, {"x", "inexact", "Head"}}]

A function equivalent to InexactNumberQ:

Wolfram Language code: inq = (NumberQ[#] && (MatchQ[#, _Real | Complex[_Real, _] | Complex[_, _Real]]))&;
Wolfram Language code: numbers = {0, 1., 2`10, 3 / 4, 5 + 6 I, N[Pi, 7] + 8 I};
Wolfram Language code: TableForm[Table[{x, InexactNumberQ[x] === inq[x]}, {x, numbers}]]
Wolfram Research (1999), InexactNumberQ, Wolfram Language function, https://reference.wolfram.com/language/ref/InexactNumberQ.html.

Text

Wolfram Research (1999), InexactNumberQ, Wolfram Language function, https://reference.wolfram.com/language/ref/InexactNumberQ.html.

CMS

Wolfram Language. 1999. "InexactNumberQ." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/InexactNumberQ.html.

APA

Wolfram Language. (1999). InexactNumberQ. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/InexactNumberQ.html

BibTeX

@misc{reference.wolfram_2026_inexactnumberq, author="Wolfram Research", title="{InexactNumberQ}", year="1999", howpublished="\url{https://reference.wolfram.com/language/ref/InexactNumberQ.html}", note=[Accessed: 13-June-2026]}

BibLaTeX

@online{reference.wolfram_2026_inexactnumberq, organization={Wolfram Research}, title={InexactNumberQ}, year={1999}, url={https://reference.wolfram.com/language/ref/InexactNumberQ.html}, note=[Accessed: 13-June-2026]}