자바스크립트 문법 11 - 객체(Object) 해답

 

* 연습과제 1

function pickRandomNumber(min, max){
    return Math.floor( Math.random() * (max-min+1) ) + min 
}
function createTesters(len){
    const group = []
    for(let i=0; i<len; i++){
        group.push(new Tester(
            pickRandomNumber(1, 10),
            pickRandomNumber(1, 10),
            pickRandomNumber(1, 5),
            pickRandomNumber(1, 10),
            pickRandomNumber(0, 50)
        ))
    }
    return group
}
function isQualityOfSleepHigh(qos){
    return qos >= 0.37 && qos <= 50
}
function countQualityOfSleepHigh(group){
    let cnt = 0
    group.forEach(tester => {
        tester.calQualityOfSleep()
        // console.log('----------------------')
        // console.log(tester.timeToAsleep)
        // console.log(tester.timeToWakeup)
        // console.log(tester.numsOfWakeup)
        // console.log(tester.numsOfMove)
        // console.log(tester.portionOfDelta)
        // console.log(tester.getQualityOfSleep)
        // console.log('----------------------')
        if(isQualityOfSleepHigh(tester.getQualityOfSleep)) cnt++
    })
    return cnt
}
function chooseBestBed(a, b, c){
    const counts = [
        {group: 'A', cnt: a},
        {group: 'B', cnt: b},
        {group: 'C', cnt: c}
    ]
    counts.sort( (c1, c2) => c2.cnt - c1.cnt)
    alert(`${counts[0].group} bed is choosen to a new bed this year !`)
}

function Tester(timeToAsleep, timeToWakeup, numsOfWakeup, numsOfMove, portionOfDelta){
    this.timeToAsleep = timeToAsleep
    this.timeToWakeup = timeToWakeup
    this.numsOfWakeup = numsOfWakeup
    this.numsOfMove = numsOfMove
    this.portionOfDelta = portionOfDelta
    this.qualityOfSleep = 0
}
Tester.prototype = {
    calQualityOfSleep(){
        this.qualityOfSleep = this.portionOfDelta / (this.timeToAsleep * this.timeToWakeup * this.numsOfWakeup * this.numsOfMove)
    },
    get getQualityOfSleep(){
        return this.qualityOfSleep
    }
}

const aGroup = createTesters(100), bGroup = createTesters(100), cGroup = createTesters(100)

console.log(aGroup)
console.log(bGroup)
console.log(cGroup)

console.log('A group cnt ', countQualityOfSleepHigh(aGroup))
console.log('B group cnt ', countQualityOfSleepHigh(bGroup))
console.log('C  group cnt ', countQualityOfSleepHigh(cGroup))

chooseBestBed(
    countQualityOfSleepHigh(aGroup),
    countQualityOfSleepHigh(bGroup),
    countQualityOfSleepHigh(cGroup)
)

 

* 연습과제 2

가까운 역간 요금 테이블 계산

function Station(name, lat, lon){
    this.name = name
    this.lat = lat
    this.lon = lon
}

Station.prototype.calDistance = function(dest){
    const R = 6371e3; // 지구의 반지름 (meter) 
    const φ1 = this.lat * Math.PI / 180 // 좌표를 라디안 단위로 변환 
    const φ2 = dest.lat * Math.PI / 180
    const Δφ = (dest.lat - this.lat) * Math.PI / 180
    const Δλ = (dest.lon - this.lon) * Math.PI / 180
    const a = Math.sin(Δφ / 2) * Math.sin(Δφ / 2) + Math.cos(φ1) * Math.cos(φ2) * Math.sin(Δλ / 2) * Math.sin(Δλ / 2)
    const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
    const d = R * c // meter
    return d
}

const seoul = new Station('서울역', 37.55620110026294, 126.97223116703012)
const daejeon = new Station('대전역', 36.332516127741, 127.43421099777726)
const daegu = new Station('동대구역', 35.88049128950934, 128.62837657353532)
const busan = new Station('부산역', 35.116613680508806, 129.04009077373016)

const stations = [seoul, daejeon, daegu, busan]
const priceTable = {}

for(let i=0 ; i<stations.length-1; i++){
    const d = stations[i].calDistance(stations[i+1])  // 요금 계산
    priceTable[`${stations[i].name}-${stations[i+1].name}`] = parseInt(d / 1000) * 100
}
console.table(priceTable)

최종 역간 요금 테이블 계산

function Station(name, lat, lon){
    this.name = name
    this.lat = lat
    this.lon = lon
}

Station.prototype.calDistance = function(dest){
    const R = 6371e3; // 지구의 반지름 (meter) 
    const φ1 = this.lat * Math.PI / 180 // 좌표를 라디안 단위로 변환 
    const φ2 = dest.lat * Math.PI / 180
    const Δφ = (dest.lat - this.lat) * Math.PI / 180
    const Δλ = (dest.lon - this.lon) * Math.PI / 180
    const a = Math.sin(Δφ / 2) * Math.sin(Δφ / 2) + Math.cos(φ1) * Math.cos(φ2) * Math.sin(Δλ / 2) * Math.sin(Δλ / 2)
    const c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a))
    const d = R * c // meter
    return d
}

const seoul = new Station('서울역', 37.55620110026294, 126.97223116703012)
const daejeon = new Station('대전역', 36.332516127741, 127.43421099777726)
const daegu = new Station('동대구역', 35.88049128950934, 128.62837657353532)
const busan = new Station('부산역', 35.116613680508806, 129.04009077373016)

const stations = [seoul, daejeon, daegu, busan]
const priceTable = {}

for(let i=0 ; i<stations.length-1; i++){
    const d = stations[i].calDistance(stations[i+1])  // 요금 계산
    priceTable[`${stations[i].name}-${stations[i+1].name}`] = parseInt(d / 1000) * 100
}
console.table(priceTable)

const prices = Object.values(priceTable) 
const stationNames = Object.keys(priceTable)

function sum(start, end){
    let sum = 0
    for(let i=start; i<=end; i++){
        sum += prices[i]
    }
    return sum
}
for(let i=0; i<prices.length-1; i++){
    for(let j=i+1; j<prices.length; j++){
        priceTable[`${stationNames[i].split('-')[0]}-${stationNames[j].split('-')[1]}`] = sum(i, j) // 여러 지점간 요금은 i부터 j까지의 요금을 합산함
    }
}

console.table(priceTable)

 

* 연습과제 3

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>자바스크립트 연습</title>
    <link rel='stylesheet' href='style.css'/>
</head>
<body>
    <div id="canvas"></div>
    <script src='app.js'></script>
</body>
</html>

body{
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100vh;
    background: lightgoldenrodyellow;
}
#canvas{
    width: 60%;
    margin: 100px auto;

    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
}

.circle{
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: chocolate;
    color: white;
    font-weight: bold;
    font-size: 1.3rem;
    margin: 10px;

    display: flex;
    flex-wrap: wrap;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    user-select: none;
    opacity: 0;
    transition: all .5s;
}
.circle:hover{
    opacity: 0.8;
}

const hairColors = ['black', 'brown', 'yellow', 'white', 'gold']
const hairTypes = ['curly', 'straight', 'wavy', 'coily']
const glasses = [true, false]
const heights = [150, 160, 170, 180, 190, 200]
const weights = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150]

const personNum = 10000
const persons = []
const classifiedFeatures = {}

function pickFeature(feature){
    return feature[Math.floor(Math.random()*feature.length)]
}

function displayFeatures(features){
    const canvas = document.getElementById('canvas')
    for(let feature in features){
        const featureEl = document.createElement('div')
        featureEl.className = 'circle'
        // featureEl.style.opacity = '1'
        featureEl.innerHTML = `
            <h1>${features[feature]}</h1>
            <div>${feature}</div>
        `
        canvas.appendChild(featureEl)
    }
}

function classify(person){
    for(let feat in person){
        let featValue = person[feat]
        switch(feat){
            case 'glasses':
                featValue = featValue ? 'put on glasses' : 'no glasses'
                break
            case 'height':
                featValue = featValue + 'cm'
                break
            case 'weight':
                featValue = featValue + 'kg'
        }
        
        if(!classifiedFeatures[featValue]) classifiedFeatures[featValue] = 0
        classifiedFeatures[featValue]++
    }
}

function Person(hairColor, hairType, glasses, height, weight){
    this.hairColor = hairColor
    this.hairType = hairType
    this.glasses = glasses
    this.height = height
    this.weight = weight
}

for(let i=0; i<personNum; i++){
    persons.push(new Person(
        pickFeature(hairColors),
        pickFeature(hairTypes),
        pickFeature(glasses),
        pickFeature(heights),
        pickFeature(weights)
    ))
}

console.log(persons)

persons.forEach(classify)

console.log(classifiedFeatures)

displayFeatures(classifiedFeatures)