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 :heart: and support.

Install

Install with npm:

1$ npm install --save has-value

Heads up!

Breaking changes in v2.0! See the release history for details.

Usage

1const has = require('has-value');
2
3console.log(has()) //=> true
4console.log(has('foo')) //=> true

Works for:

• booleans
• functions
• numbers
• strings
• nulls
• object
• arrays

isEmpty

To do the opposite and test for empty values, do:

1const isEmpty = (...args) => !has(...args);

Supported types

Arrays

1console.log(has({ foo: { bar: ['a'] } }, 'foo.bar'));    //=> true
2console.log(has({ foo: { bar: [0] } }, 'foo.bar'));      //=> true
3console.log(has({ foo: { bar: [[[]]] } }, 'foo.bar'));   //=> false
4console.log(has({ foo: { bar: [[], []] } }, 'foo.bar')); //=> false
5console.log(has({ foo: { bar: [] } }, 'foo.bar'));       //=> false

Booleans

1console.log(has({ foo: { bar: true } }, 'foo.bar'));  //=> true
2console.log(has({ foo: { bar: false } }, 'foo.bar')); //=> true

Buffers

1console.log(has({ foo: { bar: new Buffer() } }, 'foo.bar'));      //=> false
2console.log(has({ foo: { bar: new Buffer('foo') } }, 'foo.bar')); //=> true

Dates

Dates are always true.

1console.log(has({ foo: { bar: new Date() } }, 'foo.bar')); //=> true

Errors

Returns false if err.message is an empty string.

1console.log(has({ foo: { bar: new Error() } }, 'foo.bar'));      //=> false
2console.log(has({ foo: { bar: new Error('foo') } }, 'foo.bar')); //=> true

Functions

Functions are always true.

1console.log(has({ foo: { bar: function(foo) {} } }, 'foo.bar')); //=> true
2console.log(has({ foo: { bar: function() {} } }, 'foo.bar'));    //=> true

Maps

1console.log(has({ foo: { bar: new Map() } }, 'foo.bar'));                 //=> false
2console.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.

1console.log(has({ foo: { bar: null } }, 'foo.bar')); //=> true

Objects

1console.log(has({ foo: { bar: {} } }, 'foo.bar')); //=> false
2console.log(has({ foo: { bar: { a: 'a' }} } }, 'foo.bar'));        //=> true
3console.log(has({ foo: { bar: { foo: undefined } } }, 'foo.bar')); //=> false
4console.log(has({ foo: { bar: { foo: null } } }, 'foo.bar'));      //=> true

Numbers

1console.log(has({ foo: { bar: 1 } }, 'foo.bar')); //=> true
2console.log(has({ foo: { bar: 0 } }, 'foo.bar')); //=> true

Regular expressions

1console.log(has({ foo: { bar: new RegExp() } }, 'foo.bar'));      //=> false
2console.log(has({ foo: { bar: new RegExp('foo') } }, 'foo.bar')); //=> true

Sets

1console.log(has({ foo: { bar: new Set() } }, 'foo.bar'));               //=> false
2console.log(has({ foo: { bar: new Set(['foo', 'bar']) } }, 'foo.bar')); //=> true

Strings

1console.log(has({ foo: { bar: 'a' } }, 'foo.bar')); //=> true
2console.log(has({ foo: { bar: '' } }, 'foo.bar'));  //=> false

Undefined

1console.log(has({ foo: { bar:  } }, 'foo.bar'));          //=> false
2console.log(has({ foo: { bar: void 0 } }, 'foo.bar'));    //=> false
3console.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

• zero always returns true
• array now recurses, so that an array of empty arrays will return false
• null now returns true

About

1$ npm install && npm test

1$ 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

Author

Jon Schlinkert

• LinkedIn Profile
• GitHub Profile
• Twitter Profile

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.