如何创建一个广播按钮？

要创建单选按钮，需使用HTML的并确保同组按钮具有相同name属性，1. 使用并设置相同name以形成互斥选择组；2. 每个按钮需有唯一id和value，并用提升可访问性；3. 添加checked属性可设置默认选中项；4. 可通过CSS调整样式如缩放或隐藏原生外观；5. 可用JavaScript通过querySelector获取选中值或监听change事件实时响应，正确使用name、id、label是关键，完整实现后表单可正常提交所选值。

Creating a radio button is straightforward using HTML. Radio buttons are used when you want users to select only one option from a set of choices. Here's how to do it properly:

1. Use the <input> element with type="radio"

Each radio button is created using the <input> tag with the type attribute set to "radio". To group them so only one can be selected at a time, make sure they all have the same name attribute.

Example:

<form>
  <p>Choose your favorite fruit:</p>
  <input type="radio" id="apple" name="fruit" value="apple">
  <label for="apple">Apple</label><br>

  <input type="radio" id="banana" name="fruit" value="banana">
  <label for="banana">Banana</label><br>

  <input type="radio" id="orange" name="fruit" value="orange">
  <label for="orange">Orange</label>
</form>

2. Key points to remember

• Same name: All radio buttons in a group must share the same name so they are treated as a single group.
• Unique id and value: Each button should have a unique id (for labeling) and a value (what gets submitted with the form).
• Use <label>: Always pair each radio button with a <label> using the for attribute (matching the id). This improves accessibility and usability (users can click the label to select the button).

3. Make one option selected by default

Use the checked attribute to pre-select a default option.

<input type="radio" id="apple" name="fruit" value="apple" checked>
<label for="apple">Apple</label>

4. Styling with CSS (optional)

You can style radio buttons using CSS. While default styles vary by browser, you can customize them using pseudo-elements or hide the original and create custom designs.

Simple example:

input[type="radio"] {
  transform: scale(1.2);
  margin-right: 8px;
}

5. Handling with JavaScript (optional)

To get the selected value in JavaScript:

const selectedValue = document.querySelector('input[name="fruit"]:checked').value;
console.log(selectedValue);

You can also listen for changes:

document.querySelectorAll('input[name="fruit"]').forEach(radio => {
  radio.addEventListener('change', function() {
    console.log('Selected:', this.value);
  });
});

Basically, that’s it — radio buttons are simple in HTML but powerful when grouped and labeled correctly. Just remember: same name, unique ids, and use labels.

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