mathjs/docs/reference/functions/isNaN.md

Function isNaN

Test whether a value is NaN (not a number). The function supports types number, BigNumber, Fraction, Unit and Complex.

The function is evaluated element-wise in case of Array or Matrix input.

Syntax

math.isNaN(x)

Parameters

Parameter	Type	Description
x	number | BigNumber | Fraction | Unit | Array | Matrix	Value to be tested

Returns

Type	Description
boolean	Returns true when x is NaN. Throws an error in case of an unknown data type.

Examples

math.isNaN(3);                     // returns false
math.isNaN(NaN);                   // returns true
math.isNaN(0);                     // returns false
math.isNaN(math.bignumber(NaN));   // returns true
math.isNaN(math.bignumber(0));     // returns false
math.isNaN(math.fraction(-2, 5));  // returns false
math.isNaN('-2');                  // returns false
math.isNaN([2, 0, -3, NaN]');      // returns [false, false, false, true]

See also

isNumeric, isNegative, isPositive, isZero, isInteger