Reflect.setPrototypeOf()

The static Reflect.setPrototypeOf() method is the same method as Object.setPrototypeOf(), except for its return type. It sets the prototype (i.e., the internal [[Prototype]] property) of a specified object to another object or to null, and returns true if the operation was successful, or false otherwise.

Syntax

Reflect.setPrototypeOf(target, prototype)

Parameters

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

Return value

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

Exceptions

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

Description

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

Examples

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.
let target = {}
let proto = Object.create(target)
Reflect.setPrototypeOf(target, proto)  // false

Specifications

Specification
ECMAScript (ECMA-262)
The definition of 'Reflect.setPrototypeOf' in that specification.

Browser compatibility

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See also