单选按钮在提交时切换

Question

因此，当我 select 标记为黑色的单选按钮并单击添加按钮以显示该值时，标记为红色的单选按钮得到 selected 并显示该值。这是我的代码：

function add() {
  var total;

  if (document.getElementById("btn").checked = true) {
    total = 0
  } else if (document.getElementById("2ndbtn").checked = true) {
    total = 1;
  } else {
    total = 0
  };

  document.getElementById("show").innerHTML = total;
}

<!DOCTYPE html>
<html>

<head>
  <title> </title>
</head>

<body>
  <h5>what color is the car?</h5>
  <input type="radio" name="q1" value="0" id="btn" /> red
  <input type="radio" name="q1" value="0" id="2ndbtn" /> black
  <button type="button" onclick="add();">add</button>
  <p id="show"></p>
  <script src="questions.js"></script>
</body>

</html>

Answer 1

当您在代码中执行此操作时：

if(document.getElementById("btn").checked = true){
total = 0
}else if(document.getElementById("2ndbtn").checked = true){
    total = 1;
}else{total = 0};

您实际上是将检查值设置为真，而不是检查是否为真。因此，您必须将其更改为：

if(document.getElementById("btn").checked){
    total = 0
}else if(document.getElementById("2ndbtn").checked){
    total = 1;
}else{total = 0};

那么应该可以了。

单选按钮在提交时切换

radio button switches upon submission

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