ES2015-compliant shim for Object.is - differentiates between -0 and +0

Usage no npm install needed!

<script type="module">
  import objectIs from 'https://cdn.skypack.dev/object-is';


object-is Version Badge

Build Status dependency status dev dependency status License Downloads

npm badge

ES2015-compliant shim for Object.is - differentiates between -0 and +0, and can compare to NaN.

Essentially, Object.is returns the same value as === - but true for NaN, and false for -0 and +0.

This package implements the es-shim API interface. It works in an ES3-supported environment and complies with the spec.


Object.is = require('object-is');
var assert = require('assert');

assert.ok(Object.is(undefined, undefined));
assert.ok(Object.is(null, null));
assert.ok(Object.is(true, true));
assert.ok(Object.is(false, false));
assert.ok(Object.is('foo', 'foo'));

var arr = [1, 2];
assert.ok(Object.is(arr, arr));
assert.notOk(Object.is(arr, [1, 2]));

assert.ok(Object.is(0, 0));
assert.ok(Object.is(-0, -0));
assert.notOk(Object.is(0, -0));

assert.ok(Object.is(NaN, NaN));
assert.ok(Object.is(Infinity, Infinity));
assert.ok(Object.is(-Infinity, -Infinity));


Simply clone the repo, npm install, and run npm test