JavaScript设计模式面试真题(一)

一

题目

• 画出UML类图
• 用ES6语法写出该示例

解答

class Car{
    constructor(number,name){
        this.number=number
        this.name=name
    }
}

class kuaizhe extends Car{
    constructor(number,name){
        super(number,name)
        this.price=1    }
}

class zhuanche extends Car{
    constructor(number,name){
        super(number,name)
        this.price=2
    }
}

class Trip{
    constructor(car){
        this.car=car
    }

    start(){
        console.log(`开始，名称：${this.car.name},车牌号：${this.car.number}`)
    }

    end(){
        console.log(`借宿，金额：${this.car.price*5`)
    }
}

let car =new kuaiche(100,'kuai')
let trip=new Trip(car)
trip.start()
trip.end()

二

问题

解答

UML

class Car{
    constructor(num){
        this.num=num
    }
}

// 摄像头
class Camera{
    // constructor
    shot(car){
        retrun {
            num:car.num
            inTime:Date.now()
        }
    }
}

class Screen{
    show(car,inTime){
        console.log(car.num)
        console.log(Date.now()-inTime)
    }
}

class Park{
    constructor(floors){
        this.floors=floors||[]
        this.camera=new Camera()
        this.screen=new Screen()
        this.carList={}
    }
    in(car){
        const info =this.camera.shot(car)

        const i =parseInt(Math.random()*100%100)
        const place=this.floors[0].place[i]
        place.in()
        info.place=place

        this.carList[car.num]=info
    }
    out(car){
        cosnt info=this.carList[car.num]
        cosnt place=info.place
        place.out()

        this.screen.show(car,info.inTime)

        delete this.carList[car.num]
    }
    emptyNum(){
        return this.floors.map(floor=>{
            return `${floor.index}层还有${floor.emptyPlace}`
        }).join('\n')
    }
}
// 层
class Floor{
    constructor(index,places){
        this.index=index
        this.palces=places||[]
    }

    emptyPlaceNum(){
        let num=0
        this.places.forEach(p=>{
            if(!p.empty){
                num+=1
            }
        })
        return num

    }
}

class Place(){
    constructor(){
        this.empty=true
    }
    in(){
        this.empty=false
    }
    out(){
        this.empty=true
    }
}

//test------------------
const floors=[]
for(let i=0;i<3;i++){
    const places=[]
    for (let j =0;j<100;j++){
        places[j]=new Place()
    }
    floors[i]=new Floor(i+1,places)
}

const park=new Park(floors)

const car1= new Car(100)
const car2= new Car(200)
const car3 =new Car(300)

console.log('car1 in')
console.log(park.emptyNum())
park.in(car1)

park.out(car1)