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IntegerQ

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[expr∈Integers] can be used to try to determine whether an expression is mathematically equal to an integer.

Examples

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Basic Examples (1)

IntegerQ tests whether an expression is explicitly an integer:

Applications (2)

Test whether an array consists of all integers:

Make a test for Gaussian integers:

Properties & Relations (2)

Integers have head Integer:

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

Possible Issues (1)

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

It is necessary to use symbolic simplification first:

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