The Object setPrototypeOf() method

Learning JavaScript? Download my free JavaScript Handbook 🔥

---

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.

Usage:

Object.setPrototypeOf(object, prototype)

Example:

const Animal = {}
Animal.isAnimal = true

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

console.log('-------')
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