Create a Set of Checkboxes Question!

HTML-CSS
1

Tell us what’s happening:

Hello. I learned that id attribute should be only 1 in one page, but radio buttons&checkboxes need multiple id attributes when I use label for="". Anyone can explain why?? Or is it just exceptional for those two sets in HTML? Thank you.

Your code so far


<h2>CatPhotoApp</h2>
<main>
  <p>Click here to view more <a href="#">cat photos</a>.</p>
  
  <a href="#"><img src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back."></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">
    <label for="indoor"><input id="indoor" type="radio" name="indoor-outdoor"> Indoor</label>
    <label for="outdoor"><input id="outdoor" type="radio" name="indoor-outdoor"> Outdoor</label><br>
    <input type="text" placeholder="cat photo URL" required>
    <button type="submit">Submit</button>
  </form>
</main>

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36.

Link to the challenge:
https://learn.freecodecamp.org/responsive-web-design/basic-html-and-html5/create-a-set-of-checkboxes

2

yes you are correct id should be unique to page .

but you can give the same name to group of radio buttons or checkboxes