333

schangxiang@126.com

2025-09-19 18966e02fb573c7e2bb0c6426ed792b38b910940

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
#is-nan <sup>[![Version Badge][2]][1]</sup>
 
[![Build Status][3]][4]
[![dependency status][5]][6]
[![dev dependency status][7]][8]
[![License][license-image]][license-url]
[![Downloads][downloads-image]][downloads-url]
 
[![npm badge][11]][1]
 
[![browser support][9]][10]
 
ES6-compliant shim for Number.isNaN - the global isNaN returns false positives.
 
This package implements the [es-shim API](https://github.com/es-shims/api) interface. It works in an ES3-supported environment and complies with the [spec](http://www.ecma-international.org/ecma-262/6.0/#sec-number.isnan).
 
## Example
 
```js
Number.isNaN = require('is-nan');
var assert = require('assert');
 
assert.notOk(Number.isNaN(undefined));
assert.notOk(Number.isNaN(null));
assert.notOk(Number.isNaN(false));
assert.notOk(Number.isNaN(true));
assert.notOk(Number.isNaN(0));
assert.notOk(Number.isNaN(42));
assert.notOk(Number.isNaN(Infinity));
assert.notOk(Number.isNaN(-Infinity));
assert.notOk(Number.isNaN('foo'));
assert.notOk(Number.isNaN(function () {}));
assert.notOk(Number.isNaN([]));
assert.notOk(Number.isNaN({}));
 
assert.ok(Number.isNaN(NaN));
```
 
## Tests
Simply clone the repo, `npm install`, and run `npm test`
 
[1]: https://npmjs.org/package/is-nan
[2]: http://versionbadg.es/ljharb/is-nan.svg
[3]: https://travis-ci.org/ljharb/is-nan.svg
[4]: https://travis-ci.org/ljharb/is-nan
[5]: https://david-dm.org/ljharb/is-nan.svg
[6]: https://david-dm.org/ljharb/is-nan
[7]: https://david-dm.org/ljharb/is-nan/dev-status.svg
[8]: https://david-dm.org/ljharb/is-nan#info=devDependencies
[9]: https://ci.testling.com/ljharb/is-nan.png
[10]: https://ci.testling.com/ljharb/is-nan
[11]: https://nodei.co/npm/is-nan.png?downloads=true&stars=true
[license-image]: http://img.shields.io/npm/l/is-nan.svg
[license-url]: LICENSE
[downloads-image]: http://img.shields.io/npm/dm/is-nan.svg
[downloads-url]: http://npm-stat.com/charts.html?package=is-nan