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Object.getPrototypeOf

The Object.getPrototypeOf() method returns the prototype (i.e. the value of the internal [[Prototype]] property) of the specified object.

Syntax

Object.getPrototypeOf(obj)

Parameters

obj
The object whose prototype is to be returned.

Return value

The prototype of the given object. If there are no inherited properties, null is returned.

Examples

Using getPrototypeOf

var proto = {};
var obj = Object.create(proto);
Object.getPrototypeOf(obj) === proto; // true

Non-object coercion

In ES5, it will throw a TypeError exception if the obj parameter isn't an object. In ES2015, the parameter will be coerced to an Object.

Object.getPrototypeOf('foo');
// TypeError: "foo" is not an object (ES5 code)
Object.getPrototypeOf('foo');
// String.prototype                  (ES2015 code)

Specifications

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
getPrototypeOf 5 12 3.5 9 12.1 5
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
getPrototypeOf 1 18 4 12.1 5 1.0
Server
Node.js
getPrototypeOf Yes

Opera-specific notes

Even though older Opera versions don't support Object.getPrototypeOf() yet, Opera supports the non-standard __proto__ property since Opera 10.50.

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://wiki.developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/getPrototypeOf