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


Babel is required to process package imports. If you need a different preprocessor remove all packages first.

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


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.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.


                <html lang="en">
  <meta charset="UTF-8">
  <title>Type Ahead 👀</title>

  <form class="search-form">
    <input type="text" class="search" placeholder="City or State">
    <ul class="suggestions">
      <li>Filter for a city</li>
      <li>or a state</li>


                    html {
      box-sizing: border-box;
      font-family:'helvetica neue';
      font-size: 20px;
      font-weight: 200;
    *, *:before, *:after {
      box-sizing: inherit;
    input {
      width: 100%;

    .search-form {
      margin:50px auto;
    } {
      margin: 0;
      text-align: center;
      border: 10px solid #F7F7F7;
      width: 120%;
      left: -10%;
      position: relative;
      top: 10px;
      z-index: 2;
      border-radius: 5px;
      font-size: 40px;
      box-shadow: 0 0 5px rgba(0, 0, 0, 0.12), inset 0 0 2px rgba(0, 0, 0, 0.19);

    .suggestions {
      margin: 0;
      padding: 0;
      position: relative;
    .suggestions li {
      list-style: none;
      border-bottom: 1px solid #D8D8D8;
      box-shadow: 0 0 10px rgba(0, 0, 0, 0.14);
      transition:background 0.2s;
      text-transform: capitalize;

    .suggestions li:nth-child(even) {
      transform: perspective(100px) rotateX(3deg) translateY(2px) scale(1.001);
      background: linear-gradient(to bottom,  #ffffff 0%,#EFEFEF 100%);
    .suggestions li:nth-child(odd) {
      transform: perspective(100px) rotateX(-3deg) translateY(3px);
      background: linear-gradient(to top,  #ffffff 0%,#EFEFEF 100%);

    span.population {
      font-size: 15px;

    .details {
      text-align: center;
      font-size: 15px;

    .hl {

    .love {
      text-align: center;

    a {
      text-decoration: none;



                // assign the data to the variable endpoint
const endpoint = '';

// make a new empty array
const cities = [];
// fetch the data from the endpoint variable asynchronously
  // fetch returns a promise with the HTTP request
  .then(blob => blob.json())
  .then(data => cities.push(

function findMatches(wordToMatch, cities) {
  // filters the cities array against the user input
  return cities.filter(place => {
    const regex = new RegExp(wordToMatch, 'gi');
    // if it matches it gets returned
    return || place.state.match(regex)

function numberWithCommas(x) {
  // formats the population by separating it with commas
  return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ',');

function displayMatches() {
  // calls the findMatches function with the input value and the cities array as arguments
  const matchArray = findMatches(this.value, cities);

  // maps the matches against the regexp
  const html = => {
    const regex = new RegExp(this.value, 'gi');
    // replace the matches/user input with a span and a css class to add highlighting
    const cityName =, `<span class="hl">${this.value}</span>`);
    const stateName = place.state.replace(regex, `<span class="hl">${this.value}</span>`);
    return `
        <span class="name">${cityName}, ${stateName}</span>
        <span class="population">${numberWithCommas(place.population)}</span>
  suggestions.innerHTML = html;

// select the input input element and the unordered list element and save it in variables
const searchInput = document.querySelector('.search');
const suggestions = document.querySelector('.suggestions');

// add event listeners, which call the displayMatches function
searchInput.addEventListener('change', displayMatches);
searchInput.addEventListener('keyup', displayMatches);