obj-create&assign.js

var car = {
  wheel: 3,
  speed: () => console.log('fast')
}

var car1 = Object.create(car)
var car2 = Object.create(car)
var car3 = Object.assign({}, car)
var car4 = Object.assign(car)

car1.speed()  // fast
car2.speed()  // fast
car3.speed()  // fast
car4.speed()  // fast
console.log(car1) // {__proto__: {speed: (), wheel: 3}}
console.log(car2) // {__proto__: {speed: (), wheel: 3}}
console.log(car3) // {wheel: 3}
console.log(car4) // {wheel: 3}

car.wheel = 2
car.speed = () => console.log('very fast')

car1.speed()  // very fast
car2.speed()  // very fast
car3.speed()  // fast
car4.speed()  // very fast
console.log(car1) // {__proto__: {speed: (), wheel: 2}}
console.log(car2) // {__proto__: {speed: (), wheel: 2}}
console.log(car3) // {wheel: 3}
console.log(car4) // {wheel: 2}