Pen Settings

CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

+ add another resource

You're using npm packages, so we've auto-selected Babel for you here, which we require to process imports and make it all work. If you need to use a different JavaScript preprocessor, remove the packages in the npm tab.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource

Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

⚠️ This feature can only be used by logged in users.

Code Indentation


Save Automatically?

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

<h2>The FizzBuzz Challenge - Explained</h2>

<p>See JS comments for explanation.</p>

<button type="button" onclick="fizzBuzz()">Give Me FizzBuzz!</button>  
<p id="output-area">FizzBuzz will appear here.</p>
              * {
  font-family: Montserrat, sans-serif;

body {
   text-align: center;
  margin-top: 100px;

#output-area {
  background-color: teal;
  color: #fff;
  width: 290px;
  margin: 25px auto;
  border-radius: 8px;
  padding: 1rem;
  line-height: 1.5;


// Let's put our FizzBuzz output into an array
var output = [];

// Let's set a counter variable for the array
var count = 1;

// Let's set a counter variable for the output to know where we are when we're counting
var numberCount = 1;

// Let's write the fizzBuzz function
function fizzBuzz() {

// We start with the most complex condition in order to check for numbers that are divisible by both 3 and 5 first - if we did that later in the code, we'd lose them, because the code is read from top to bottom 
  if (count % 3 === 0 && count % 5 === 0) {
// We add the other, more simple statements
  } else if (count % 3 === 0) {
  } else if (count % 5 === 0) {
  } else {
    // We need this last statement because we're also adding numbers that aren't divisible by 3 or 5 to the array

/*Now we end the function and either write the elements of our array to the console
each time we call the function within the console using: fizzBuzz();

Output Version A - which I am not doing here, I am doing Version B */

  // count++;
  // console.log(output);

/* or we write it on the page, each time a button is clicked

Output Version B 
I am outputting each element with an empty space and a linebreak instead of a comma by using .join(" <br>"); */

  document.getElementById("output-area").innerHTML = 
"Counting: " + numberCount++ + " <br><br>" + output.join(" <br>");

🕑 One or more of the npm packages you are using needs to be built. You're the first person to ever need it! We're building it right now and your preview will start updating again when it's ready.