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[license-url]: https://github.com/Typeforce-JS/is-undefined/blob/master/LICENSE
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[unpkg-url]: https://unpkg.com/@typeforce/is-undefined/dist/index.min.js

is-undefined

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[![LICENSE][license-shield-url]][license-url]

Determine if a value is undefined.

Usage

``shell
npm install @typeforce/is-undefined --save # Install package via NPM
`

`javascript
import { expect } from "chai";
import isUndefined from "@typeforce/is-undefined";

expect(isUndefined(({ x: 42 }).y)).to.be.true;
expect(isUndefined(undefined)).to.be.true;
expect(isUndefined(void 0)).to.be.true;

expect(isUndefined(null)).to.be.false;
expect(isUndefined(42)).to.be.false;
`

This package contains TypeScript type declarations. Furthermore, the package
uses TypeScript type guards to allow type inference to influence IntelliSense.

`typescript
if (isUndefined(x)) {
// IntelliSense now knows x is undefined.
let y: undefined = x;
}
`

$3

This package can be imported via unpkg as demonstrated
below.

`html


`

Build & Test

When building the project, a folder named dist/ will be created if it does not
already exist, where the compiled code will be outputted to. Type declaration
files will also be generated and outputted to the dist/ folder.

A minified Javascript version of the entire project will be generated and
outputted to dist/index.min.js.

`shell
npm install # Installs dependencies.
npm run build # Build the project.
`

This package uses Gulp for building, and Chai
and Mocha for testing.

`shell
npm test # Run tests.
`

License

Refer to the LICENSE` file for license information.