ES6 class 继承

　　　class Phone {

                constructor(brand, price) {

                    this.brand = brand

                    this,price = price

                }

                call () {

                    console.log('我可以打电话')

                }

            }

            class SmartPhone extends Phone {

                constructor (brand, price, color, size) {

                    super(brand, price)

                    this.color = color

                    this.size = size

                }

                photo () {

                    console.log('我可以拍照')

                }

                playGame () {

                    console.log('我可以玩游戏')

                }

                call () {

                    console.log('我可以视频通话')

                }

            }

            let xiaomi = new SmartPhone('小米', 7999, '黑色', '5.1')

            xiaomi.call()

            xiaomi.photo()

            xiaomi.playGame()