object-is

What is object-is?

The 'object-is' npm package provides a utility function for comparing two values, determining if they are the same value. This is particularly useful for edge cases in JavaScript comparisons, such as NaN, +0, and -0, where traditional equality checks (== or ===) might fail or not behave as expected.

What are object-is's main functionalities?

Exact equality comparison

This feature allows for the comparison of two values to determine if they are exactly the same, including more accurate handling of special JavaScript cases like NaN and +/-0.

const objectIs = require('object-is');
console.log(objectIs('foo', 'foo')); // true
console.log(objectIs(window, window)); // true
console.log(objectIs('foo', 'bar')); // false
console.log(objectIs(0, -0)); // false
console.log(objectIs(NaN, NaN)); // true

Other packages similar to object-is

is-equal

A package that offers deep equality comparison. Unlike 'object-is', which only checks if two values are the same, 'is-equal' can compare objects and arrays deeply, making it suitable for more complex data structures.

deep-equal

This package also provides deep equality checks, similar to 'is-equal'. It compares the contents of objects and arrays recursively, which is more comprehensive than the simple value comparison provided by 'object-is'.

README

object-is

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.

Example

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

assert.ok(Object.is());
assert.ok(Object.is(undefined));
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.equal(Object.is(arr, [1, 2]), false);

assert.ok(Object.is(0, 0));
assert.ok(Object.is(-0, -0));
assert.equal(Object.is(0, -0), false);

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

Tests

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

Changelog

v1.1.6 - 2024-02-27

Commits

• [actions] reuse common workflows f8d0c06
• [actions] use node/install instead of node/run 90fc019
• [actions] update workflows 37339d8
• [meta] use npmignore to autogenerate an npmignore file a257c19
• [readme] fix badges 50af053
• [Dev Deps] update eslint, @ljharb/eslint-config, @es-shims/api, safe-publish-latest, tape 86058c6
• [Dev Deps] update eslint, @ljharb/eslint-config, aud, auto-changelog, functions-have-names, has-symbols, tape d5484eb
• [actions] update rebase action to use reusable workflow 68075c5
• [actions] update codecov uploader f12fbb2
• [Dev Deps] update eslint, @ljharb/eslint-config, aud, auto-changelog, has-symbols, tape 43eb235
• [Dev Deps] update @es-shims/api, @ljharb/eslint-config, aud, npmignore, tape f306966
• [readme] add actions and codecov badges e443b4a
• [readme] remove travis badge 5165adc
• [Dev Deps] update eslint, @ljharb/eslint-config, tape e7ccf56
• [Deps] update call-bind, define-properties a3052db
• [readme] fix URLs ac37ea6
• [readme] assert.notOk -> assert.equal 7fe769f
• [Deps] update call-bind b965cd3
• [Dev Deps] update tape a737830
• [Deps] update define-properties, es-abstract 441eafb