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

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 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 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.getPrototypeOf' in that specification.
Standard  
ECMAScript Latest Draft (ECMA-262)
The definition of 'Object.getPrototypeOf' in that specification.
Living Standard  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support5 Yes3.5912.15
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic support Yes Yes Yes4 No Yes 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

Document Tags and Contributors

 Last updated by: fscholz,