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.'
  

image.png

• 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__