Create a Set of Radio Buttons(单选按钮，类似于单选题)

Create a Set of Radio Buttons

说明：

类比是最好的学习方式，当你搞不清一个概念时，最好在生活中找到对应的案例。

单选就是你只能在多个选项中选择一个，就好比你有很多追求者，但却只能选择一个结婚。

多选一的场景就用radio button(单选按钮)

单选按钮只是input输入框的一种类型。

每一个单选按钮都应该嵌套在它自己的label(标签)元素中。

注意：所有关联的单选按钮应该使用相同的name属性。

下面是一个单选按钮的例子：

<label><input type="radio" name="indoor-outdoor"> Indoor</label>

给你的表单添加两个单选按钮，一个叫indoor，另一个叫outdoor。

原始代码：

<link href="https://fonts.gdgdocs.org/css?family=Lobster" rel="stylesheet" type="text/css">
<style>
  .red-text {
    color: red;
  }

  h2 {
    font-family: Lobster, Monospace;
  }

  p {
    font-size: 16px;
    font-family: Monospace;
  }

  .thick-green-border {
    border-color: green;
    border-width: 10px;
    border-style: solid;
    border-radius: 50%;
  }

  .smaller-image {
    width: 100px;
  }
</style>

<h2 class="red-text">CatPhotoApp</h2>

<p>Click here for <a href="#">cat photos</a>.</p>

<a href="#"><img class="smaller-image thick-green-border" alt="A cute orange cat lying on its back" src="/images/relaxing-cat.jpg"></a>

<p>Things cats love:</p>
<ul>
  <li>cat nip</li>
  <li>laser pointers</li>
  <li>lasagna</li>
</ul>
<p>Top 3 things cats hate:</p>
<ol>
  <li>flea treatment</li>
  <li>thunder</li>
  <li>other cats</li>
</ol>
<form action="/submit-cat-photo">
  <input type="text" placeholder="cat photo URL" required>
  <button type="submit">Submit</button>
</form>

调试代码：

<link href="https://fonts.gdgdocs.org/css?family=Lobster" rel="stylesheet" type="text/css">
<style>
  .red-text {
    color: red;
  }

  h2 {
    font-family: Lobster, Monospace;
  }

  p {
    font-size: 16px;
    font-family: Monospace;
  }

  .thick-green-border {
    border-color: green;
    border-width: 10px;
    border-style: solid;
    border-radius: 50%;
  }

  .smaller-image {
    width: 100px;
  }
</style>
<h2 class="red-text">CatPhotoApp</h2>

<p>Click here for <a href="#">cat photos</a>.</p>

<a href="#"><img class="smaller-image thick-green-border" alt="A cute orange cat lying on its back" src="/images/relaxing-cat.jpg"></a>

<p>Things cats love:</p>
<ul>
  <li>cat nip</li>
  <li>laser pointers</li>
  <li>lasagna</li>
</ul>
<p>Top 3 things cats hate:</p>
<ol>
  <li>flea treatment</li>
  <li>thunder</li>
  <li>other cats</li>
</ol>
<form action="/submit-cat-photo">
  <input type="text" placeholder="cat photo URL" required>
  <button type="submit">Submit</button>
</form>

<label><input type="radio" name="indoor-outdoor"> Indoor</label>
<label><input type="radio" name="indoor-outdoor"> outdoor</label>