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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.

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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

Specification
ECMAScript Language Specification
# sec-object.getprototypeof

Browser compatibility

Desktop Mobile Server
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet Deno Node.js
getPrototypeOf
5
12
3.5
9
12.1
5
1
18
4
12.1
5
1.0
1.0
0.10.0

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

© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/getPrototypeOf

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Last Updated 2022-04-28T06:04:39Z