has-value 
Returns true if a value exists, false if empty. Works with deeply nested values using object paths.
Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your
Install
Install with npm:
$ npm install --save has-valueHeads up!
Breaking changes in v2.0! See the release history for details.
Usage
const has = require('has-value');
console.log(has()) //=> true
console.log(has('foo')) //=> trueWorks for:
- booleans
- functions
- numbers
- strings
- nulls
- object
- arrays
isEmpty
To do the opposite and test for empty values, do:
const isEmpty = (...args) => !has(...args);Supported types
Arrays
console.log(has({ foo: { bar: ['a'] } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: [0] } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: [[[]]] } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: [[], []] } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: [] } }, 'foo.bar')); //=> falseBooleans
console.log(has({ foo: { bar: true } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: false } }, 'foo.bar')); //=> trueBuffers
console.log(has({ foo: { bar: new Buffer() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new Buffer('foo') } }, 'foo.bar')); //=> trueDates
Dates are always true.
console.log(has({ foo: { bar: new Date() } }, 'foo.bar')); //=> trueErrors
Returns false if err.message is an empty string.
console.log(has({ foo: { bar: new Error() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new Error('foo') } }, 'foo.bar')); //=> trueFunctions
Functions are always true.
console.log(has({ foo: { bar: function(foo) {} } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: function() {} } }, 'foo.bar')); //=> trueMaps
console.log(has({ foo: { bar: new Map() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new Map([['foo', 'bar']]) } }, 'foo.bar')); //=> trueNull
null is always true, as it's assumed that this is a user-defined value, versus undefined which is not.
console.log(has({ foo: { bar: null } }, 'foo.bar')); //=> trueObjects
console.log(has({ foo: { bar: {} } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: { a: 'a' }} } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: { foo: undefined } } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: { foo: null } } }, 'foo.bar')); //=> trueNumbers
console.log(has({ foo: { bar: 1 } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: 0 } }, 'foo.bar')); //=> trueRegular expressions
console.log(has({ foo: { bar: new RegExp() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new RegExp('foo') } }, 'foo.bar')); //=> trueSets
console.log(has({ foo: { bar: new Set() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new Set(['foo', 'bar']) } }, 'foo.bar')); //=> trueStrings
console.log(has({ foo: { bar: 'a' } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: '' } }, 'foo.bar')); //=> falseUndefined
console.log(has({ foo: { bar: } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: void 0 } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: undefined } }, 'foo.bar')); //=> falseRelease history
v2.0.0
Breaking changes
- Now returns false if the first argument is not an object, function or array, and the second argument is not a string or array.
v1.0.0
zeroalways returns truearraynow recurses, so that an array of empty arrays will returnfalsenullnow returns true
About
Contributing
Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.
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:
$ npm install && npm testBuilding docs
(This project's readme.md is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the .verb.md readme template.)
To generate the readme, run the following command:
$ npm install -g verbose/verb#dev verb-generate-readme && verbRelated projects
You might also be interested in these projects:
- define-property: Define a non-enumerable property on an object. Uses Reflect.defineProperty when available, otherwise Object.defineProperty. | homepage
- get-value: Use property paths like 'a.b.c' to get a nested value from an object. Even works… more | homepage
- set-value: Create nested values and any intermediaries using dot notation (
'a.b.c') paths. | homepage - unset-value: Delete nested properties from an object using dot notation. | homepage
Contributors
| Commits | Contributor |
|---|---|
| 32 | jonschlinkert |
| 2 | rmharrison |
| 1 | wtgtybhertgeghgtwtg |
Author
Jon Schlinkert
License
Copyright © 2018, Jon Schlinkert. Released under the MIT License.
This file was generated by verb-generate-readme, v0.6.0, on March 03, 2018.