javascript - 在 javascript 中创建多项选择选项

Question

我创建了一个 HTML 多项选择题。我面临如何验证它的问题。下面是 HTML 代码:

<h1>JavaScript is ______ Language.</h1><br>
<form>
  <input type="radio" name="choice" value="Scripting"> Scripting
  <input type="radio" name="choice" value="Programming"> Programming
  <input type="radio" name="choice" value="Application"> Application
  <input type="radio" name="choice" value="None of These"> None of These
</form>
<button>Submit Answer</button>

当用户单击提交按钮时，应该有一个警报，根据所选内容显示一条消息。

• 如果未选择任何选项，则警告框应显示“请选择选项答案”。
• 如果选择“脚本”选项，则警告框应显示“答案正确!”
• 如果选择了与“脚本”不同的选项，则警告框应显示“答案错误”。

我想在 JavaScript 中创建此验证。

Answer 1

你必须使用onclick属性和更多js

1. 将事件处理程序附加到您的按钮
2. 获取单选元素值
3. 比较

var submitAnswer = function() {

  var radios = document.getElementsByName('choice');
  var val= "";
  for (var i = 0, length = radios.length; i < length; i++) {
      if (radios[i].checked) {
         val = radios[i].value; 
         break;
       }
  }
  
  if (val == "" ) {
    alert('please select choice answer');
  } else if ( val == "Scripting" ) {
    alert('Answer is correct !');
  } else {
    alert('Answer is wrong');
  }
};

<h1>JavaScript is ______ Language.</h1><br>
<form >
<input type="radio" name="choice" value="Scripting"> Scripting
<input type="radio" name="choice" value="Programming"> Programming
<input type="radio" name="choice" value="Application"> Application
<input type="radio" name="choice" value="None of These"> None of These
</form>
<button onclick="submitAnswer()">Submit Answer</button>