Pen Settings



CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource


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


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.


Auto Save

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.


        <div id="logindiv">
            <select id="lang">
                <option value="en">English</option>
                <option value="es">Spanish</option>
            <input type="button" value="Login" id="login" />
        <h1 id='greeting'></h1>




                (function(global, $) {
    // 'new' an object
    var Greetr = function(firstName, lastName, language) {
        return new Greetr.init(firstName, lastName, language);   
    // hidden within the scope of the IIFE and never directly accessible
    var supportedLangs = ['en', 'es'];
    // informal greetings
    var greetings = {
        en: 'Hello',
        es: 'Ola'
    // formal greetings
    var formalGreetings = {
        en: 'Greetings',
        es: 'Saludos'
    // logger messages
    var logMessages = {
        en: 'Logged in',
        es: 'Inició sesión'
    // prototype holds methods (to save memory space)
    Greetr.prototype = {
        // 'this' refers to the calling object at execution time
        fullName: function() {
            return this.firstName + ' ' + this.lastName;
        validate: function() {
            // check that is a valid language
            // references the externally inaccessible 'supportedLangs' within the closure
            if (supportedLangs.indexOf(this.language)  === -1) {
                //Throw an error
                throw "Invalid language";
        // retrieve messages from object by referring to properties using [] syntax
        greeting: function() {
            return greetings[this.language] + ' ' + this.firstName + '!';
        formalGreeting: function() {
            return formalGreetings[this.language] + ', ' + this.fullName();  
        // chainable methods return their own containing object
        greet: function(formal) {
            var msg;
            // if undefined or null it will be coerced to 'false'
            if(formal) {
                msg = this.formalGreeting();
            } else {
                msg = this.greeting();
            if (console) {
            // 'this' refers to the calling object at execution time
            // makes the method chainable
            return this;
        log: function() {
            if (console) {
                console.log(logMessages[this.language] + ': ' + this.fullName()); 
            // make chainable
            return this;
        // set the language
        setLang: function(lang) {
            this.language = lang;
            // validate
            // make chainable
            return this;
        HTMLGreeting: function(selector, formal) {
            if (!$) {
                throw 'jQuery not loaded';   
            if (!selector) {
                throw 'Missing jQuery selector';   
            // determine the message
            var msg;
            if (formal) {
                msg = this.formalGreeting();   
            else {
                msg = this.greeting();   
            // inject the message in the chosen place in the DOM
            // make chainable
            return this;
    // the actual object is created here, allowing us to 'new' an object without calling 'new'
    Greetr.init = function(firstName, lastName, language) {
        var self = this;
        self.firstName = firstName || '';
        self.lastName = lastName || '';
        self.language = language || 'en';
    // trick borrowed from jQuery so we don't have to use the 'new' keyword
    Greetr.init.prototype = Greetr.prototype;
    // attach our Greetr to the global object, and provide a shorthand '$G' for ease our poor fingers
    global.Greetr = global.G$ = Greetr;

}(window, jQuery));

// gets a new object (the architecture allows us to not have to use the 'new' keyword here)
var g = G$('Rich', 'Holman');

// use our chainable methods

// let's use our object on the click of the login button
$('#login').click(function() {
    // create a new 'Greetr' object (let's pretend we know the name from the login)
    var loginGrtr = G$('Rich', 'Holman');
     // fire off an HTML greeting, passing the '#greeting' as the selector and the chosen language, and log the welcome as well
    loginGrtr.setLang($('#lang').val()).HTMLGreeting('#greeting', true).log();