index.js

let cards = []
let cardsEl = document.querySelector("#card-el")
let sum = 0
let hasBlackJack = false
let isAlive = false
let start = false
let sumEl = document.querySelector("#sum-el")
let message = ""
let messageEl = document.getElementById("message-el")

let player = {
    name: "mazhum",
    chips: 145
}

let playerEl = document.getElementById("player-el")
playerEl.textContent = player.name + " : $" + player.chips

function getRandomCard () {
    let randCard = Math.floor( Math.random() * 13) + 1
    if (randCard == 1){
        return 11
    }else if (randCard > 10) {
        return 10
    }else {
        return randCard
    }
}

function startGame () {
    if (start == false) {
        isAlive = true
        let firstCard = getRandomCard()
        let secondCard = getRandomCard()
        cards.push(firstCard)
        cards.push(secondCard)
        for (let i = 0;i < cards.length;i++){
            sum += cards[i]
        }
        renderGame()
        start = true
    }
}

function renderGame () {
    cardsEl.textContent = "Card : "
    for (let i=0; i<cards.length; i++ ) {
        cardsEl.textContent += cards[i] +" "
    }
    sumEl.textContent = "Sum : " + sum 
    if (sum <= 20){
        message = "Do you want to draw a new card "
    }else if (sum === 21) {
        message = "You've got the black jack !"
        hasBlackJack = true
    }else {
        message = "You're out of the game"
        isAlive = false
    }
    messageEl.textContent = message
}

function newCard () {
    if (isAlive == true && hasBlackJack != true ){
    let card = getRandomCard()
    sum += card
    cards.push(card)
    renderGame()
    }
}