has-values
Returns true if any values exist, false if empty. Works for booleans, functions, numbers, strings, nulls, objects and arrays.
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Install
Install with npm:
$ npm install --save has-values
Usage
const has = require('has-values');
Create an isEmpty
function by returning the inverse of the result from has-values:
const isEmpty = val => !has(val);
Supported types
Arrays
console.log(has(['a'])); //=> true
console.log(has([0])); //=> true
console.log(has([[[]]])); //=> false
console.log(has([[], []])); //=> false
console.log(has([])); //=> false
Booleans
console.log(has(true)); //=> true
console.log(has(false)); //=> true
Buffers
console.log(has(new Buffer())); //=> false
console.log(has(new Buffer('foo'))); //=> true
Dates
Dates are always true.
console.log(has(new Date())); //=> true
Errors
Returns false
if err.message
is an empty string.
console.log(has(new Error())); //=> false
console.log(has(new Error('foo'))); //=> true
Functions
Functions are always true.
console.log(has(function(foo) {})); //=> true
console.log(has(function() {})); //=> true
Maps
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.
console.log(has(null)); //=> true
Objects
console.log(has({})); //=> false
console.log(has({ a: 'a' }})); //=> true
console.log(has({ foo: undefined })); //=> false
console.log(has({ foo: null })); //=> true
Numbers
console.log(has(1)); //=> true
console.log(has(0)); //=> true
Regular expressions
console.log(has(new RegExp())); //=> false
console.log(has(new RegExp('foo'))); //=> true
Sets
console.log(has(new Set())); //=> false
console.log(has(new Set(['foo', 'bar']))); //=> true
Strings
console.log(has('a')); //=> true
console.log(has('')); //=> false
Undefined
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
andbuffer
v1.0.0
- adds support for
Map
andSet
zero
always returns truearray
now recurses, so that an array of empty arrays will returnfalse
null
now 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:
- has-value: Returns true if a value exists, false if empty. Works with deeply nested values using… more | homepage
- is-number: Returns true if the value is a number. comprehensive tests. | homepage
- is-plain-object: Returns true if an object was created by the
Object
constructor. | homepage - isobject: Returns true if the value is an object and not an array or null. | homepage
- kind-of: Get the native type of a value. | homepage
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 January 30, 2018.