The Object setPrototypeOf() method

Find out all about the JavaScript setPrototypeOf() method of the Object object

Set the prototype of an object.

While you’re here, see my guide on JavaScript Prototypal Inheritance

Accepts two arguments: the object and the prototype.


Object.setPrototypeOf(object, prototype)


const Animal = {}
Animal.isAnimal = true

const Mammal = Object.create(Animal)
Mammal.isMammal = true

Mammal.isAnimal //true

const dog = Object.create(Animal)

dog.isAnimal  //true
console.log(dog.isMammal)  //undefined

Object.setPrototypeOf(dog, Mammal)

console.log(dog.isAnimal) //true
console.log(dog.isMammal) //true

Download my free JavaScript Handbook!