212 lines
6.0 KiB
Markdown
212 lines
6.0 KiB
Markdown
# 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)
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> Returns true if any values exist, false if empty. Works for booleans, functions, numbers, strings, nulls, objects and arrays.
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Please consider following this project's author, [Jon Schlinkert](https://github.com/jonschlinkert), and consider starring the project to show your :heart: and support.
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## Install
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Install with [npm](https://www.npmjs.com/):
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```sh
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$ npm install --save has-values
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```
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## Usage
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```js
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const has = require('has-values');
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```
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Create an `isEmpty` function by returning the inverse of the result from has-values:
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```js
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const isEmpty = val => !has(val);
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```
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## Supported types
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### Arrays
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```js
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console.log(has(['a'])); //=> true
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console.log(has([0])); //=> true
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console.log(has([[[]]])); //=> false
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console.log(has([[], []])); //=> false
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console.log(has([])); //=> false
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```
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### Booleans
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```js
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console.log(has(true)); //=> true
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console.log(has(false)); //=> true
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```
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### Buffers
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```js
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console.log(has(new Buffer())); //=> false
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console.log(has(new Buffer('foo'))); //=> true
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```
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### Dates
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Dates are always true.
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```js
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console.log(has(new Date())); //=> true
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```
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### Errors
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Returns `false` if `err.message` is an empty string.
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```js
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console.log(has(new Error())); //=> false
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console.log(has(new Error('foo'))); //=> true
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```
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### Functions
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Functions are always true.
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```js
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console.log(has(function(foo) {})); //=> true
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console.log(has(function() {})); //=> true
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```
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### Maps
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```js
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console.log(has(new Map())); //=> false
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console.log(has(new Map([['foo', 'bar']]))); //=> true
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```
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### Null
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`null` is always true, as it's assumed that this is a user-defined value, versus `undefined` which is not.
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```js
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console.log(has(null)); //=> true
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```
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### Objects
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```js
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console.log(has({})); //=> false
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console.log(has({ a: 'a' }})); //=> true
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console.log(has({ foo: undefined })); //=> false
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console.log(has({ foo: null })); //=> true
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```
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### Numbers
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```js
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console.log(has(1)); //=> true
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console.log(has(0)); //=> true
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```
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### Regular expressions
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```js
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console.log(has(new RegExp())); //=> false
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console.log(has(new RegExp('foo'))); //=> true
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```
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### Sets
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```js
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console.log(has(new Set())); //=> false
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console.log(has(new Set(['foo', 'bar']))); //=> true
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```
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### Strings
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```js
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console.log(has('a')); //=> true
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console.log(has('')); //=> false
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```
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## Undefined
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```js
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console.log(has()); //=> false
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console.log(has(void 0)); //=> false
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console.log(has(undefined)); //=> false
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```
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## Release history
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### v2.0.0
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* no longer supports numbers as a string
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* optimizations
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* adds support for `regex` and `buffer`
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### v1.0.0
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* adds support for `Map` and `Set`
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* `zero` always returns true
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* `array` now recurses, so that an array of empty arrays will return `false`
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* `null` now returns true
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## About
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<details>
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<summary><strong>Contributing</strong></summary>
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Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).
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</details>
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<details>
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<summary><strong>Running Tests</strong></summary>
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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:
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```sh
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$ npm install && npm test
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```
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</details>
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<details>
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<summary><strong>Building docs</strong></summary>
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_(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.)_
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To generate the readme, run the following command:
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```sh
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$ npm install -g verbose/verb#dev verb-generate-readme && verb
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```
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</details>
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### Related projects
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You might also be interested in these projects:
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* [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.")
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* [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.")
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* [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.")
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* [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.")
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* [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.")
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### Author
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**Jon Schlinkert**
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* [linkedin/in/jonschlinkert](https://linkedin.com/in/jonschlinkert)
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* [github/jonschlinkert](https://github.com/jonschlinkert)
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* [twitter/jonschlinkert](https://twitter.com/jonschlinkert)
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### License
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Copyright © 2018, [Jon Schlinkert](https://github.com/jonschlinkert).
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Released under the [MIT License](LICENSE).
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***
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_This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.6.0, on January 30, 2018._ |