class Base { model = 'base' constructor() { console.log(this.model) } } class Derived extends Base { model = 'derived' } let obj = new Derived() console.log(obj.model) 打印结果: base derived
实例化 Derived 的对象时,父类 Base 构造函数中,Derived 里面定义的 model 还没有绑定到 this,所以只能取到'base'。如果想得到'derived'是否只能重写 Derived 的 constructor ?想问或者有没有更优雅的办法。
还有试了一下 es7 的静态属性
class Base { static model = 'base' constructor() { console.log(this.constructor.model) } } class Derived extends Base { static model = 'derived' } let obj = new Derived() 打印结果: derived
虽然可以生效,但是不能通过对象实例(this)访问。
