@stdlib/assert-is-nan

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isNaN

Test if a value is NaN.

Installation

npm install @stdlib/assert-is-nan

Usage

var isnan = require( '@stdlib/assert-is-nan' );

isnan( value )

Tests if a value is NaN.

var Number = require( '@stdlib/number-ctor' );

var bool = isnan( NaN );
// returns true

bool = isnan( new Number( NaN ) );
// returns true

bool = isnan( 3.14 );
// returns false

bool = isnan( null );
// returns false

isnan.isPrimitive( value )

Tests if a value is a NaN primitive number.

var Number = require( '@stdlib/number-ctor' );

var bool = isnan.isPrimitive( NaN );
// returns true

bool = isnan.isPrimitive( 3.14 );
// returns false

bool = isnan.isPrimitive( new Number( NaN ) );
// returns false

isnan.isObject( value )

Tests if a value is a Number object having a value of NaN.

var Number = require( '@stdlib/number-ctor' );

var bool = isnan.isObject( NaN );
// returns false

bool = isnan.isObject( new Number( NaN ) );
// returns true

Examples

var Number = require( '@stdlib/number-ctor' );
var Symbol = require( '@stdlib/symbol-ctor' );
var isnan = require( '@stdlib/assert-is-nan' );

var bool = isnan( NaN );
// returns true

bool = isnan( new Number( NaN ) );
// returns true

bool = isnan( 5 );
// returns false

bool = isnan( '5' );
// returns false

bool = isnan( null );
// returns false

bool = isnan( Symbol( 'NaN' ) );
// returns false

See Also

• @stdlib/assert-is-number: test if a value is a number.

Notice

This package is part of stdlib, a standard library for JavaScript and Node.js, with an emphasis on numerical and scientific computing. The library provides a collection of robust, high performance libraries for mathematics, statistics, streams, utilities, and more.

For more information on the project, filing bug reports and feature requests, and guidance on how to develop stdlib, see the main project repository.

Community

License

See LICENSE.

Copyright

Copyright © 2016-2026. The Stdlib Authors.