Javascript变量未按预期添加值

Question

我在html和javascript中都有此代码 HTML

f

*

我的问题是，当我在文本框中输入正确答案时，correct_ans变量没有添加

Answer 1

检查正确答案后，应初始化变量result。

function getResult() {
  let correct_ans = 0;
  let answer_one = document.getElementById("question_one").value;  
  if (answer_one === "abuja") correct_ans++;

  let result = "You answered " + correct_ans + " correctly.";
  document.getElementById("result").innerHTML = result;
}

<div class="container">
  <div class="question1">
    <p>What is the capital of Nigeria</p><br>
    <input type="text" id="question_one">

  </div>

  <button id="button" onclick="getResult();">Submit</button>

</div>
<!--end of container-->

<div class="button_after">

  <h1 id="result"></h1>

</div>
<!--end of button_after-->

Answer 2

您在更新变量abuja之前声明了变量correct_ans。将其放在if条件之后。如果您要添加其他问题，则需要将correct_ans = 0的初始声明放在函数之外，否则您总是会得到0或1。

function getResult() {
  let answer_one = document.getElementById("question_one").value;
  
  let correct_ans = 0;
  
  if (answer_one === "abuja") {
    correct_ans++;
  }
  let result = "You answered " + correct_ans + " correctly.";

  document.getElementById("result").innerHTML = result;
}

<div class="container">
  <div class="question1">
    <p>What is the capital of Nigeria</p><br>
    <input type="text" id="question_one">

  </div>

  <button id="button" onclick="getResult();">Submit</button>

</div>
<!--end of container-->

<div class="button_after">

  <h1 id="result"></h1>

</div>
<!--end of button_after-->

Answer 3

在您的代码中，对结果的评估是在correct_ans增量之前。 试试这个吧。

function getResult() {
  let answer_one = document.getElementById("question_one").value;
  let correct_ans = 0;
  let result = "";

  if (answer_one === "abuja") {
    correct_ans++;
  }
  result = You answered " + correct_ans + " correctly.
  document.getElementById("result").innerHTML = result;
}