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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.

Examples

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

Notes

In ES5, it will throw a TypeError exception if the obj parameter isn't an object. In ES6, the parameter will be coerced to an Object.

Object.getPrototypeOf("foo");
// TypeError: "foo" is not an object (ES5 code)
Object.getPrototypeOf("foo");
// String.prototype                  (ES6 code)

Specifications

Specification Status Comment
ECMAScript 5.1 (ECMA-262)
The definition of 'Object.getPrototypeOf' in that specification.
Standard Initial definition.
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Object.getProtoypeOf' in that specification.
Standard  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 5 3.5 (1.9.1) 9 12.10 5
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? ? ? ? ? ?

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

Document Tags and Contributors

Last updated by: fscholz,