JarCastinghas-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-value
Heads 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')) //=> true
Works 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')); //=> false
Booleans
console.log(has({ foo: { bar: true } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: false } }, 'foo.bar')); //=> true
Buffers
console.log(has({ foo: { bar: new Buffer() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new Buffer('foo') } }, 'foo.bar')); //=> true
Dates
Dates are always true.
console.log(has({ foo: { bar: new Date() } }, 'foo.bar')); //=> true
Errors
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')); //=> true
Functions
Functions are always true.
console.log(has({ foo: { bar: function(foo) {} } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: function() {} } }, 'foo.bar')); //=> true
Maps
console.log(has({ foo: { bar: new Map() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new Map([['foo', 'bar']]) } }, 'foo.bar')); //=> true
Null
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')); //=> true
Objects
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')); //=> true
Numbers
console.log(has({ foo: { bar: 1 } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: 0 } }, 'foo.bar')); //=> true
Regular expressions
console.log(has({ foo: { bar: new RegExp() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new RegExp('foo') } }, 'foo.bar')); //=> true
Sets
console.log(has({ foo: { bar: new Set() } }, 'foo.bar')); //=> false
console.log(has({ foo: { bar: new Set(['foo', 'bar']) } }, 'foo.bar')); //=> true
Strings
console.log(has({ foo: { bar: 'a' } }, 'foo.bar')); //=> true
console.log(has({ foo: { bar: '' } }, 'foo.bar')); //=> false
Undefined
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')); //=> false
Release 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 test
Building 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 && verb
Related 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.