The static Reflect.setPrototypeOf() method is the same method as Object.setPrototypeOf(). It sets the prototype (i.e., the internal [[Prototype]] property) of a specified object to another object or to null.


Reflect.setPrototypeOf(target, prototype)


The target object of which to set the prototype.
The object's new prototype (an object or null).

Return value

A Boolean indicating whether or not the prototype was successfully set.


A TypeError, if target is not an Object or if prototype is neither an object nor null.


The Reflect.setPrototypeOf method changes the prototype (i.e. the value of the internal [[Prototype]] property) of the specified object.


Using Reflect.setPrototypeOf()

Reflect.setPrototypeOf({}, Object.prototype); // true

// It can change an object's [[Prototype]] to null.
Reflect.setPrototypeOf({}, null); // true

// Returns false if target is not extensible.
Reflect.setPrototypeOf(Object.freeze({}), null); // false

// Returns false if it cause a prototype chain cycle.
var target = {};
var proto = Object.create(target);
Reflect.setPrototypeOf(target, proto); // false


Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Reflect.setPrototypeOf' in that specification.
Standard Initial definition.
ECMAScript 2017 Draft (ECMA-262)
The definition of 'Reflect.setPrototypeOf' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support 49 42 (42) No support No support No support
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support No support 42.0 (42) No support No support No support

See also

Document Tags and Contributors

 Contributors to this page: eduardoboucas, gingerik, fscholz, YuichiNukiyama, ziyunfei
 Last updated by: eduardoboucas,