The Number.isInteger()
method determines whether the
passed value is an integer.
The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request.
The source for this interactive example is stored in a GitHub
repository. If you'd like to contribute to the interactive examples project, please
clone https://github.com/mdn/interactive-examples
and send us a pull request.
Syntax
Number.isInteger(value)
Parameters
value
- The value to be tested for being an integer.
Return value
A Boolean
indicating whether or not the given value is an integer.
Description
If the target value is an integer, return true
, otherwise return
false
. If the value is NaN
or Infinity
, return
false
. The method will also return true
for floating point
numbers that can be represented as integer.
Examples
Using isInteger
Number.isInteger(0); // true
Number.isInteger(1); // true
Number.isInteger(-100000); // true
Number.isInteger(99999999999999999999999); // true
Number.isInteger(0.1); // false
Number.isInteger(Math.PI); // false
Number.isInteger(NaN); // false
Number.isInteger(Infinity); // false
Number.isInteger(-Infinity); // false
Number.isInteger('10'); // false
Number.isInteger(true); // false
Number.isInteger(false); // false
Number.isInteger([1]); // false
Number.isInteger(5.0); // true
Number.isInteger(5.000000000000001); // false
Number.isInteger(5.0000000000000001); // true
Polyfill
Number.isInteger = Number.isInteger || function(value) {
return typeof value === 'number' &&
isFinite(value) &&
Math.floor(value) === value;
};
Specifications
Browser compatibility
BCD tables only load in the browser
See also
- The
Number
object it belongs to.