javascript - 我的 javascript 代码没有链接到 dom

Question

我面临的挑战是创建一个识别素数的函数，并且在我将 const 数字链接到输入并将函数链接到按钮之前，该函数在控制台上运行得很好。

const btn = document.querySelector('.btn1')
if (btn) {
  btn.addEventListener('click', isitPrime)
}

function isitPrime() {
  const number = document.querySelector('.input1').innerHTML
  const answer = document.querySelector('.answer')
  let isPrime = true
  for (let i = 2; i < number; i++) {
    if (number % i === 0) {
      isPrime = false
      answer.innerHTML = (`${number} is not prime
            ${number} can be divided by ${i}`)
    }
    if (isPrime) {
      answer.innerHTML = (`${number} is prime`)
    }
  }
}

<input type="text" class="input1">
<button class="btn1">click here</button> <br/><br/>
<div class="answer"></div>

如何解决这个问题？

Answer 1

为了获取输入的值，您必须使用 value 属性而不是 innerHtml 属性，如下所示:

const btn = document.querySelector('.btn1')
if(btn){
    btn.addEventListener('click', isitPrime)
}
function isitPrime(){
    // here we get 'value' property instead of 'innerHtml' property
    const number = document.querySelector('.input1').value
    const answer = document.querySelector('.answer')
    let isPrime = true
    for(let i = 2; i < number; i++){
        if(number % i === 0){
            isPrime = false
            answer.innerHTML = (`${number} is not prime
            ${number} can be divided by ${i}`)
        }
        if(isPrime){
            answer.innerHTML = (`${number} is prime`)
        }
    }
}

<input type="text" class="input1">
<button class="btn1">click here</button>  <br/><br/>
<div class="answer"></div>