has-values

Returns true if any values exist, false if empty. Works for booleans, functions, numbers, strings, nulls, objects and arrays.

Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your ❤️ and support.

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 and buffer

v1.0.0

adds support for Map and Set
zero always returns true
array now recurses, so that an array of empty arrays will return false
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

This file was generated by verb-generate-readme, v0.6.0, on January 30, 2018.

jonschlinkert/has-values