WOLFRAM

IntegerQ[expr]

gives True if expr is an integer, and False otherwise.

Details

  • IntegerQ[expr] returns False unless expr is manifestly an integer (i.e. has head Integer).
  • Simplify[exprIntegers] can be used to try to determine whether an expression is mathematically equal to an integer.

Examples

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Basic Examples  (1)Summary of the most common use cases

IntegerQ tests whether an expression is explicitly an integer:

Out[1]=1
Out[2]=2

Applications  (2)Sample problems that can be solved with this function

Test whether an array consists of all integers:

Out[1]=1
Out[2]=2

Make a test for Gaussian integers:

Out[2]=2

Properties & Relations  (2)Properties of the function, and connections to other functions

Integers have head Integer:

Out[2]=2

An expression may have head Integer, but IntegerQ gives False:

Out[1]=1
Out[2]=2

Possible Issues  (1)Common pitfalls and unexpected behavior

Expressions that do not evaluate to integers explicitly will still give False:

Out[2]=2

It is necessary to use symbolic simplification first:

Out[3]=3
Wolfram Research (1988), IntegerQ, Wolfram Language function, https://reference.wolfram.com/language/ref/IntegerQ.html (updated 1999).
Wolfram Research (1988), IntegerQ, Wolfram Language function, https://reference.wolfram.com/language/ref/IntegerQ.html (updated 1999).

Text

Wolfram Research (1988), IntegerQ, Wolfram Language function, https://reference.wolfram.com/language/ref/IntegerQ.html (updated 1999).

Wolfram Research (1988), IntegerQ, Wolfram Language function, https://reference.wolfram.com/language/ref/IntegerQ.html (updated 1999).

CMS

Wolfram Language. 1988. "IntegerQ." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 1999. https://reference.wolfram.com/language/ref/IntegerQ.html.

Wolfram Language. 1988. "IntegerQ." Wolfram Language & System Documentation Center. Wolfram Research. Last Modified 1999. https://reference.wolfram.com/language/ref/IntegerQ.html.

APA

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

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

BibTeX

@misc{reference.wolfram_2025_integerq, author="Wolfram Research", title="{IntegerQ}", year="1999", howpublished="\url{https://reference.wolfram.com/language/ref/IntegerQ.html}", note=[Accessed: 09-July-2025 ]}

@misc{reference.wolfram_2025_integerq, author="Wolfram Research", title="{IntegerQ}", year="1999", howpublished="\url{https://reference.wolfram.com/language/ref/IntegerQ.html}", note=[Accessed: 09-July-2025 ]}

BibLaTeX

@online{reference.wolfram_2025_integerq, organization={Wolfram Research}, title={IntegerQ}, year={1999}, url={https://reference.wolfram.com/language/ref/IntegerQ.html}, note=[Accessed: 09-July-2025 ]}

@online{reference.wolfram_2025_integerq, organization={Wolfram Research}, title={IntegerQ}, year={1999}, url={https://reference.wolfram.com/language/ref/IntegerQ.html}, note=[Accessed: 09-July-2025 ]}