https://github.com/bttmly/is-pojo

check if something is a POJO (Plain Old Javascript Object)
https://github.com/bttmly/is-pojo

Last synced: 17 days ago
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check if something is a POJO (Plain Old Javascript Object)

• Host: GitHub
• URL: https://github.com/bttmly/is-pojo
• Owner: bttmly
• Created: 2014-10-13T18:43:42.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2015-04-05T07:27:08.000Z (about 10 years ago)
• Last Synced: 2025-04-04T18:22:01.798Z (about 1 month ago)
• Language: JavaScript
• Homepage:
• Size: 211 KB
• Stars: 7
• Watchers: 1
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md

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README

        
# is-pojo [![Build Status](https://travis-ci.org/nickb1080/is-pojo.svg?branch=master)](https://travis-ci.org/nickb1080/is-pojo) [![NPM version](https://badge.fury.io/js/is-pojo.svg)](http://badge.fury.io/js/is-pojo)

### Installation

`npm install is-pojo`

### Usage

```js

var isPojo = require("is-pojo");

isPojo({}) // true

// anything besides an absolutely plain object will return false.

// here are examples from the tests:

function Foo () {}

function Bar () {}

Bar.prototype.constructor = Object;

isPojo(function () {}) // false

isPojo([]) // false

isPojo(new Date()) // false

isPojo(true); // false

isPojo("abc"); // false

isPojo(123); // false

isPojo(new RegExp()); // false

isPojo(null); // false

isPojo(undefined); // false

isPojo(Object.create({})); // false

isPojo(new Foo()); // false

isPojo(new Bar()); // false

isPojo({constructor: Foo}); // true

```

### Why?

The [other module on npm](https://www.npmjs.org/package/is-plain-object) that I found to do this checks an object's `constructor` property against `Object`. This approach is error-prone since there's nothing special about the `constructor` property; you can set it willy-nilly (see example above).

In contrast, an object's _actual_ prototype (obtained with `Object.getPrototypeOf`) is the real and only definition of an object's nature -- even in the possible case that its prototype has been changed after creation (either though the spec compliant `Object.setPrototypeOf` or by changing the commonly implemented `__proto__ ` property).