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
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
|
# has-values [](https://www.npmjs.com/package/has-values) [](https://npmjs.org/package/has-values) [](https://npmjs.org/package/has-values) [](https://travis-ci.org/jonschlinkert/has-values)
> Returns true if any values exist, false if empty. Works for booleans, functions, numbers, strings, nulls, objects and arrays.
Please consider following this project's author, [Jon Schlinkert](https://github.com/jonschlinkert), and consider starring the project to show your :heart: and support.
## Install
Install with [npm](https://www.npmjs.com/):
```sh
$ npm install --save has-values
```
## Usage
```js
const has = require('has-values');
```
Create an `isEmpty` function by returning the inverse of the result from has-values:
```js
const isEmpty = val => !has(val);
```
## Supported types
### Arrays
```js
console.log(has(['a'])); //=> true
console.log(has([0])); //=> true
console.log(has([[[]]])); //=> false
console.log(has([[], []])); //=> false
console.log(has([])); //=> false
```
### Booleans
```js
console.log(has(true)); //=> true
console.log(has(false)); //=> true
```
### Buffers
```js
console.log(has(new Buffer())); //=> false
console.log(has(new Buffer('foo'))); //=> true
```
### Dates
Dates are always true.
```js
console.log(has(new Date())); //=> true
```
### Errors
Returns `false` if `err.message` is an empty string.
```js
console.log(has(new Error())); //=> false
console.log(has(new Error('foo'))); //=> true
```
### Functions
Functions are always true.
```js
console.log(has(function(foo) {})); //=> true
console.log(has(function() {})); //=> true
```
### Maps
```js
console.log(has(new Map())); //=> false
console.log(has(new Map([['foo', 'bar']]))); //=> true
```
### Null
`null` is always true, as it's assumed that this is a user-defined value, versus `undefined` which is not.
```js
console.log(has(null)); //=> true
```
### Objects
```js
console.log(has({})); //=> false
console.log(has({ a: 'a' }})); //=> true
console.log(has({ foo: undefined })); //=> false
console.log(has({ foo: null })); //=> true
```
### Numbers
```js
console.log(has(1)); //=> true
console.log(has(0)); //=> true
```
### Regular expressions
```js
console.log(has(new RegExp())); //=> false
console.log(has(new RegExp('foo'))); //=> true
```
### Sets
```js
console.log(has(new Set())); //=> false
console.log(has(new Set(['foo', 'bar']))); //=> true
```
### Strings
```js
console.log(has('a')); //=> true
console.log(has('')); //=> false
```
## Undefined
```js
console.log(has()); //=> false
console.log(has(void 0)); //=> false
console.log(has(undefined)); //=> false
```
## Release history
### v2.0.0
* no longer supports numbers as a string
* optimizations
* adds support for `regex` and `buffer`
### v1.0.0
* adds support for `Map` and `Set`
* `zero` always returns true
* `array` now recurses, so that an array of empty arrays will return `false`
* `null` now returns true
## About
<details>
<summary><strong>Contributing</strong></summary>
Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).
</details>
<details>
<summary><strong>Running Tests</strong></summary>
Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:
```sh
$ npm install && npm test
```
</details>
<details>
<summary><strong>Building docs</strong></summary>
_(This project's readme.md is generated by [verb](https://github.com/verbose/verb-generate-readme), please don't edit the readme directly. Any changes to the readme must be made in the [.verb.md](.verb.md) readme template.)_
To generate the readme, run the following command:
```sh
$ npm install -g verbose/verb#dev verb-generate-readme && verb
```
</details>
### Related projects
You might also be interested in these projects:
* [has-value](https://www.npmjs.com/package/has-value): Returns true if a value exists, false if empty. Works with deeply nested values using… [more](https://github.com/jonschlinkert/has-value) | [homepage](https://github.com/jonschlinkert/has-value "Returns true if a value exists, false if empty. Works with deeply nested values using object paths.")
* [is-number](https://www.npmjs.com/package/is-number): Returns true if the value is a number. comprehensive tests. | [homepage](https://github.com/jonschlinkert/is-number "Returns true if the value is a number. comprehensive tests.")
* [is-plain-object](https://www.npmjs.com/package/is-plain-object): Returns true if an object was created by the `Object` constructor. | [homepage](https://github.com/jonschlinkert/is-plain-object "Returns true if an object was created by the `Object` constructor.")
* [isobject](https://www.npmjs.com/package/isobject): Returns true if the value is an object and not an array or null. | [homepage](https://github.com/jonschlinkert/isobject "Returns true if the value is an object and not an array or null.")
* [kind-of](https://www.npmjs.com/package/kind-of): Get the native type of a value. | [homepage](https://github.com/jonschlinkert/kind-of "Get the native type of a value.")
### Author
**Jon Schlinkert**
* [linkedin/in/jonschlinkert](https://linkedin.com/in/jonschlinkert)
* [github/jonschlinkert](https://github.com/jonschlinkert)
* [twitter/jonschlinkert](https://twitter.com/jonschlinkert)
### License
Copyright © 2018, [Jon Schlinkert](https://github.com/jonschlinkert).
Released under the [MIT License](LICENSE).
***
_This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.6.0, on January 30, 2018._
|
