130 lines
3.2 KiB
Markdown
130 lines
3.2 KiB
Markdown
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# has-value [](https://www.npmjs.com/package/has-value) [](https://npmjs.org/package/has-value) [](https://travis-ci.org/jonschlinkert/has-value)
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> Returns true if a value exists, false if empty. Works with deeply nested values using object paths.
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## Install
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Install with [npm](https://www.npmjs.com/):
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```sh
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$ npm install has-value --save
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```
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**Works for:**
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* booleans
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* functions
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* numbers (pass `true` as the last arg to treat zero as a value instead of falsey)
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* strings
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* nulls
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* object
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* arrays
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## Usage
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Works with nested object paths or a single value:
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```js
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var hasValue = require('has-value');
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hasValue({a: {b: {c: 'foo'}}} 'a.b.c');
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//=> true
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hasValue('a');
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//=> true
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hasValue('');
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//=> false
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hasValue(1);
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//=> true
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hasValue(0);
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//=> false
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hasValue(0, true); // pass `true` as the last arg to treat zero as a value
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//=> true
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hasValue({a: 'a'}});
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//=> true
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hasValue({}});
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//=> false
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hasValue(['a']);
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//=> true
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hasValue([]);
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//=> false
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hasValue(function(foo) {}); // function length/arity
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//=> true
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hasValue(function() {});
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//=> false
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hasValue(true);
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hasValue(false);
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//=> true
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```
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## isEmpty
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To do the opposite and test for empty values, do:
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```js
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function isEmpty(o, isZero) {
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return !hasValue.apply(hasValue, arguments);
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}
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```
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## Related projects
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You might also be interested in these projects:
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* [get-object](https://www.npmjs.com/package/get-object): Get a property from an object using dot (object path) notation. | [homepage](https://github.com/jonschlinkert/get-object)
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* [get-property](https://www.npmjs.com/package/get-property): Get a nested property or its value from an object using simple `a.b.c` paths. | [homepage](https://github.com/jonschlinkert/get-property)
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* [get-value](https://www.npmjs.com/package/get-value): Use property paths (`a.b.c`) to get a nested value from an object. | [homepage](https://github.com/jonschlinkert/get-value)
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* [set-value](https://www.npmjs.com/package/set-value): Create nested values and any intermediaries using dot notation (`'a.b.c'`) paths. | [homepage](https://github.com/jonschlinkert/set-value)
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## Contributing
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Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](https://github.com/jonschlinkert/has-value/issues/new).
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## Building docs
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Generate readme and API documentation with [verb](https://github.com/verbose/verb):
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```sh
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$ npm install verb && npm run docs
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```
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Or, if [verb](https://github.com/verbose/verb) is installed globally:
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```sh
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$ verb
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```
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## Running tests
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Install dev dependencies:
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```sh
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$ npm install -d && npm test
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```
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## Author
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**Jon Schlinkert**
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* [github/jonschlinkert](https://github.com/jonschlinkert)
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* [twitter/jonschlinkert](http://twitter.com/jonschlinkert)
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## License
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Copyright © 2016, [Jon Schlinkert](https://github.com/jonschlinkert).
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Released under the [MIT license](https://github.com/jonschlinkert/has-value/blob/master/LICENSE).
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***
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_This file was generated by [verb](https://github.com/verbose/verb), v, on March 27, 2016._
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