The Object defineProperties() method

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

Creates or configures multiple object properties at once. Returns the object.

Takes 2 arguments. The first is an object upon which we’re going to create or configure the properties. The second is an object of properties.

Example:

const dog = {}
Object.defineProperties(dog, {
  breed: {
    value: 'Siberian Husky'
  }
})
console.log(dog.breed) //'Siberian Husky'

I didn’t just say breed: 'Siberian Husky' but I had to pass a property descriptor object, defined at the beginning of this page.

It can be used in conjunction with Object.getOwnPropertyDescriptors() to copy properties over from another object:

const wolf = { /*... */ }
const dog = {}
Object.defineProperties(dog, Object.getOwnPropertyDescriptors(wolf))