자바스크립트 끝말잇기

<div><span id="order">1</span>번째 참가자</div>
<div>제시어 : <span id="word"></span></div>
<input type="text">
<button>입력</button>

<script>
    let button = document.querySelector('button')
    let input = document.querySelector('input')
    let word = document.querySelector('#word')
    let currentword = ''
    let order = document.querySelector('#order')
    let currentplayer = 1;

    while (1) {
        player = (Number(prompt('몇명이서 참가하시나요?')))
        if (player === 0 || player === '') {
            alert('최소 한명이상 되어야 시작할 수 있습니다.')
        }
        else if (isNaN(player)) {
            alert('숫자를 입력해주세요')
        }
        else {
            break
        }
    }
    if (currentword === '') {
        input.setAttribute('placeholder', '제시어를 입력해주세요')
    }
    let clickbutton = function () {
        if (word.textContent === '') {
            currentword = input.value
            word.textContent = currentword
            input.value = ''
            input.setAttribute('placeholder', currentword[currentword.length - 1] + '자로 끝나는 말은?')
            currentplayer++
            order.textContent = currentplayer

        }
        else if (currentword[currentword.length - 1] === input.value[0]) {
            currentword = input.value
            word.textContent = currentword
            input.value = ''
            input.setAttribute('placeholder', currentword[currentword.length - 1] + '자로 끝나는 말은?')
            currentplayer++
            order.textContent = currentplayer
            if (currentplayer > player) {
                currentplayer = 1
                order.textContent = currentplayer
            }
            else {
                order.textContent = currentplayer
            }
        }
        else {
            alert('틀렸습니다 다시입력해주세요')
            input.value = ''
        }
    }
    button.addEventListener('click', clickbutton)
</script>