| # has-value [](https://www.npmjs.com/package/has-value) [](https://npmjs.org/package/has-value) [](https://npmjs.org/package/has-value) [](https://travis-ci.org/jonschlinkert/has-value) |
| |
| > Returns true if a value exists, false if empty. Works with deeply nested values using object paths. |
| |
| ## Install |
| |
| Install with [npm](https://www.npmjs.com/): |
| |
| ```sh |
| $ npm install --save has-value |
| ``` |
| |
| **Works for:** |
| |
| * booleans |
| * functions |
| * numbers |
| * strings |
| * nulls |
| * object |
| * arrays |
| |
| ## Usage |
| |
| Works with property values (supports object-path notation, like `foo.bar`) or a single value: |
| |
| ```js |
| var hasValue = require('has-value'); |
| |
| hasValue('foo'); |
| hasValue({foo: 'bar'}, 'foo'); |
| hasValue({a: {b: {c: 'foo'}}}, 'a.b.c'); |
| //=> true |
| |
| hasValue(''); |
| hasValue({foo: ''}, 'foo'); |
| //=> false |
| |
| hasValue(0); |
| hasValue(1); |
| hasValue({foo: 0}, 'foo'); |
| hasValue({foo: 1}, 'foo'); |
| hasValue({foo: null}, 'foo'); |
| hasValue({foo: {bar: 'a'}}}, 'foo'); |
| hasValue({foo: {bar: 'a'}}}, 'foo.bar'); |
| //=> true |
| |
| hasValue({foo: {}}}, 'foo'); |
| hasValue({foo: {bar: {}}}}, 'foo.bar'); |
| hasValue({foo: undefined}, 'foo'); |
| //=> false |
| |
| hasValue([]); |
| hasValue([[]]); |
| hasValue([[], []]); |
| hasValue([undefined]); |
| hasValue({foo: []}, 'foo'); |
| //=> false |
| |
| hasValue([0]); |
| hasValue([null]); |
| hasValue(['foo']); |
| hasValue({foo: ['a']}, 'foo'); |
| //=> true |
| |
| hasValue(function() {}) |
| hasValue(function(foo) {}) |
| hasValue({foo: function(foo) {}}, 'foo'); |
| hasValue({foo: function() {}}, 'foo'); |
| //=> true |
| |
| hasValue(true); |
| hasValue(false); |
| hasValue({foo: true}, 'foo'); |
| hasValue({foo: false}, 'foo'); |
| //=> true |
| ``` |
| |
| ## isEmpty |
| |
| To do the opposite and test for empty values, do: |
| |
| ```js |
| function isEmpty(o) { |
| return !hasValue.apply(hasValue, arguments); |
| } |
| ``` |
| |
| ## Release history |
| |
| ### v1.0.0 |
| |
| * `zero` always returns true |
| * `array` now recurses, so that an array of empty arrays will return `false` |
| * `null` now returns true |
| |
| ## About |
| |
| ### Related projects |
| |
| * [define-property](https://www.npmjs.com/package/define-property): Define a non-enumerable property on an object. | [homepage](https://github.com/jonschlinkert/define-property "Define a non-enumerable property on an object.") |
| * [get-value](https://www.npmjs.com/package/get-value): Use property paths (`a.b.c`) to get a nested value from an object. | [homepage](https://github.com/jonschlinkert/get-value "Use property paths (`a.b.c`) to get a nested value from an object.") |
| * [set-value](https://www.npmjs.com/package/set-value): Create nested values and any intermediaries using dot notation (`'a.b.c'`) paths. | [homepage](https://github.com/jonschlinkert/set-value "Create nested values and any intermediaries using dot notation (`'a.b.c'`) paths.") |
| * [unset-value](https://www.npmjs.com/package/unset-value): Delete nested properties from an object using dot notation. | [homepage](https://github.com/jonschlinkert/unset-value "Delete nested properties from an object using dot notation.") |
| |
| ### Contributing |
| |
| Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new). |
| |
| ### Contributors |
| |
| | **Commits** | **Contributor** | |
| | --- | --- | |
| | 17 | [jonschlinkert](https://github.com/jonschlinkert) | |
| | 2 | [rmharrison](https://github.com/rmharrison) | |
| |
| ### Building docs |
| |
| _(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 |
| ``` |
| |
| ### Running tests |
| |
| 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 |
| ``` |
| |
| ### Author |
| |
| **Jon Schlinkert** |
| |
| * [github/jonschlinkert](https://github.com/jonschlinkert) |
| * [twitter/jonschlinkert](https://twitter.com/jonschlinkert) |
| |
| ### License |
| |
| Copyright © 2017, [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 May 19, 2017._ |