Pen Settings

HTML

CSS

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

JavaScript

Babel includes JSX processing.

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

Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

Details

Privacy

Go PRO Window blinds lowered to protect code. Code Editor with window blinds (raised) and a light blub turned on.

Keep it secret; keep it safe.

Private Pens are hidden everywhere on CodePen, except to you. You can still share them and other people can see them, they just can't find them through searching or browsing.

Upgrade to PRO

Behavior

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.

Template

Make Template?

Templates are Pens that can be used to start other Pens quickly from the create menu. The new Pen will copy all the code and settings from the template and make a new Pen (that is not a fork). You can view all of your templates, or learn more in the documentation.

Template URL

Any Pen can act as a template (even if you don't flip the toggle above) with a special URL you can use yourself or share with others. Here's this Pen's template URL:

Screenshot

Screenshot or Custom Thumbnail

Screenshots of Pens are shown in mobile browsers, RSS feeds, to users who chose images instead of iframes, and in social media sharing.

This Pen is using the default Screenshot, generated by CodePen. Upgrade to PRO to upload your own thumbnail that will be displayed on previews of this pen throughout the site and when sharing to social media.

Upgrade to PRO

HTML

              
                You have <span>3</span> lives!
              
            
!

CSS

              
                
              
            
!

JS

              
                // The famous sequence of input's representing the KONAMI cheat code.
var KONAMI_CODE = ['UP', 'UP', 'DOWN', 'DOWN', 'LEFT', 'RIGHT', 'LEFT', 'RIGHT', 'B', 'A'];

/* 
  Takes a KeyBoardEvent and returns either a KONAMI_CODE key
  or the value null.
  
  It will return a KONAMI_CODE key when the KeyBoardEvent's key
  matches a value in the KONAMI_CODE.
  
  It will return null when the key is not part of the KONAMI_CODE.
*/
function eventToKonamiCode(event) {
  switch (event.which) {
    case 38: return 'UP';
    case 40: return 'DOWN';
    case 37: return 'LEFT';
    case 39: return 'RIGHT';
    case 66: return 'B';
    case 65: return 'A';
  }
  
  return null;
}

/*
  Checks if the codes paramater, which is an array, matches the KONAMI_CODE exactly.
*/
function isKonamiCode(codes) {
  return _.isEqual(codes, KONAMI_CODE);
}

/*
  Appends the 'code' parameter to the 'codes' parameter, if the
  code is the next part of the KONAMI_CODE sequence.
  
  If the code is not the next sequence of the KONAMI_CODE an
  empty array is returned.
*/
function codeAccumulator(codes, code) {
  // Not a normal KONAMI_CODE key so return an empty array.
  if (code === null) {
    return [];
  }
   
  codes.push(code);

  // Check if 'codes' still matches the KONAMI_CODE.
  var subKonamiCode = _.take(KONAMI_CODE, codes.length);
  if (_.isEqual(codes, subKonamiCode)) {
    return codes;
  } else {
    return []; // No match back to square one.
  }
}

var konamiStream = Rx.Observable.fromEvent(document, 'keydown')
  .map(eventToKonamiCode)
  .scan(codeAccumulator, [])
  .filter(isKonamiCode);

var livesSpan = document.querySelector('span');

konamiStream.subscribe(function() {
  alert('You entered the Konami code!');
  livesSpan.textContent = '99';
});
              
            
!
999px
Keep friends close and formatters closer.

Console