javascript - 使用按钮 onclick 提交答案后提供反馈

Question

我是 js 的新手。我已经学会了如何创建一个按钮来提交答案。但我现在想根据用户的回答向用户提供反馈。这个我试过了。

<h1>What is your choice?</h1><br>
<form id="d1">
<input type="radio" name="choice" value="Cooperate"> Cooperate
<input type="radio" name="choice" value="Betray"> Betray
</form>
<button onclick="submitAnswer(d1.choice.value)">Submit Answer</button>
<script>
var submitAnswer = function() {

  var radios = document.getElementsByName('choice');
  var val= "";
  for (var i = 0, length = radios.length; i < length; i++) {
  if (val == "Cooperate" ) {
    alert('3 points');
  } else if {val == "Betray"
    alert('0 points');
  }
};

</script>

Answer 1

试试这个

 function submitAnswer(){
   var selected = document.querySelector('input[type="radio"]:checked').value;
      if (selected === "Cooperate"){
        alert("3");
      }else{
        alert("0");
      }
  }

<h1>What is your choice?</h1><br>
<form id="d1">
   <input type="radio" name="choice" value="Cooperate"> Cooperate
   <input type="radio" name="choice" value="Betray"> Betray
</form>
<button onclick="submitAnswer()">Submit Answer</button>