Object.create()和Object.setPrototypeOf()

Object.create(proto,[propertiesObject]): 返回一个新对象,带有指定的原型对象和属性;

// Shape - 父类(superclass)
function Shape() {
  this.x = 0;
  this.y = 0;
}

// 父类的方法
Shape.prototype.move = function(x, y) {
  this.x += x;
  this.y += y;
  console.info('Shape moved.');
};

// Rectangle - 子类(subclass)
function Rectangle() {
  Shape.call(this); // call super constructor.
}

// 子类续承父类
Rectangle.prototype = Object.create(Shape.prototype);
Rectangle.prototype.constructor = Rectangle;

var rect = new Rectangle();

console.log('Is rect an instance of Rectangle?',
  rect instanceof Rectangle); // true
console.log('Is rect an instance of Shape?',
  rect instanceof Shape); // true
rect.move(1, 1); // Outputs, 'Shape moved.'

Object.setPrototypeOf() : 方法设置一个指定的对象的原型 ( 即, 内部[[Prototype]]属性）到另一个对象或 null

setPortoTypeOf方法就比较好理解了,其实就等价于Object.prototype.__proto__