UNPKG

is-number/README.md

Version:

1.91 kBMarkdownView Raw

1# is-number [![NPM version](https://badge.fury.io/js/is-number.svg)](http://badge.fury.io/js/is-number)
2
3
4> Is the value a number? Has extensive tests.
5
6## Install
7#### Install with [npm](npmjs.org):
8
9```bash
10npm i is-number --save-dev
11```
12
13## Run tests
14
15```bash
16npm test
17```
18
19## Usage
20
21```js
22var isNumber = require('is-number');
23```
24
25
26### true
27
28```js
29isNumber(5e3);
30
31isNumber(0xff);
32
33isNumber(-1.1);
34isNumber(0);
35isNumber(1);
36isNumber(1.1);
37isNumber(10);
38isNumber(10.10);
39isNumber(100);
40
41isNumber('-1.1');
42isNumber('0');
43isNumber('012');
44isNumber('0xff');
45isNumber('1');
46isNumber('1.1');
47isNumber('10');
48isNumber('10.10');
49isNumber('100');
50isNumber('5e3');
51
52isNumber(parseInt('012'));
53isNumber(parseFloat('012'));
54
55isNumber(Infinity);
56isNumber('Infinity');
57```
58
59If you want `Infinity` to be `false`, just do:
60
61```js
62var isNumber = require('is-number');
63
64function isNum(val) {
65  return isNumber(val) && isFinite(val);
66}
67```
68
69### false
70
71```js
72isNumber('3abc');
73isNumber('abc');
74isNumber('abc3');
75isNumber('null');
76isNumber('undefined');
77isNumber([1, 2, 3]);
78isNumber(function () {});
79isNumber(new Buffer('abc'));
80isNumber(null);
81isNumber(undefined);
82isNumber({abc: 'abc'});
83isNumber({});
84isNumber([]);
85```
86
87## Notes
88
89Instead of using `isFinite()`, you can also achieve similar results by using something like `((+n+1) / (+n+1) === 1))`, but this alone allows values like `null` to pass as numbers (in JavaScript, the leading `+` coerces the value to a number, [see this gist](https://gist.github.com/jonschlinkert/e30c70c713da325d0e81) for some oddities).
90
91
92## Author
93
94**Jon Schlinkert**
95 
96+ [github/jonschlinkert](https://github.com/jonschlinkert)
97+ [twitter/jonschlinkert](http://twitter.com/jonschlinkert) 
98
99## License
100Copyright (c) 2014 Jon Schlinkert, contributors.  
101Released under the MIT license
102
103***
104
105_This file was generated by [verb-cli](https://github.com/assemble/verb-cli) on September 21, 2014._
\No newline at end of file

1	`# is-number [![NPM version](https://badge.fury.io/js/is-number.svg)](http://badge.fury.io/js/is-number)`
2
3
4	`> Is the value a number? Has extensive tests.`
5
6	`## Install`
7	`#### Install with [npm](npmjs.org):`
8
9	```bash
10	`npm i is-number --save-dev`
11	```
12
13	`## Run tests`
14
15	```bash
16	`npm test`
17	```
18
19	`## Usage`
20
21	```js
22	`var isNumber = require('is-number');`
23	```
24
25
26	`### true`
27
28	```js
29	`isNumber(5e3);`
30
31	`isNumber(0xff);`
32
33	`isNumber(-1.1);`
34	`isNumber(0);`
35	`isNumber(1);`
36	`isNumber(1.1);`
37	`isNumber(10);`
38	`isNumber(10.10);`
39	`isNumber(100);`
40
41	`isNumber('-1.1');`
42	`isNumber('0');`
43	`isNumber('012');`
44	`isNumber('0xff');`
45	`isNumber('1');`
46	`isNumber('1.1');`
47	`isNumber('10');`
48	`isNumber('10.10');`
49	`isNumber('100');`
50	`isNumber('5e3');`
51
52	`isNumber(parseInt('012'));`
53	`isNumber(parseFloat('012'));`
54
55	`isNumber(Infinity);`
56	`isNumber('Infinity');`
57	```
58
59	If you want `Infinity` to be `false`, just do:
60
61	```js
62	`var isNumber = require('is-number');`
63
64	`function isNum(val) {`
65	`return isNumber(val) && isFinite(val);`
66	`}`
67	```
68
69	`### false`
70
71	```js
72	`isNumber('3abc');`
73	`isNumber('abc');`
74	`isNumber('abc3');`
75	`isNumber('null');`
76	`isNumber('undefined');`
77	`isNumber([1, 2, 3]);`
78	`isNumber(function () {});`
79	`isNumber(new Buffer('abc'));`
80	`isNumber(null);`
81	`isNumber(undefined);`
82	`isNumber({abc: 'abc'});`
83	`isNumber({});`
84	`isNumber([]);`
85	```
86
87	`## Notes`
88
89	Instead of using `isFinite()`, you can also achieve similar results by using something like `((+n+1) / (+n+1) === 1))`, but this alone allows values like `null` to pass as numbers (in JavaScript, the leading `+` coerces the value to a number, [see this gist](https://gist.github.com/jonschlinkert/e30c70c713da325d0e81) for some oddities).
90
91
92	`## Author`
93
94	`Jon Schlinkert`
95
96	`+ [github/jonschlinkert](https://github.com/jonschlinkert)`
97	`+ [twitter/jonschlinkert](http://twitter.com/jonschlinkert)`
98
99	`## License`
100	`Copyright (c) 2014 Jon Schlinkert, contributors.`
101	`Released under the MIT license`
102
103	`***`
104
105	`_This file was generated by [verb-cli](https://github.com/assemble/verb-cli) on September 21, 2014._`
\	No newline at end of file