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. You can use the CSS from another Pen by using it's URL and the proper URL extention.

+ 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.

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.

HTML

              
                <div id='wrapper'>
  
</div>
<div id='test'>
  
</div>
              
            
!

CSS

              
                body{
  background: #2C514C;
}
#wrapper {
  padding: 20px;
}
#editor {
  background: #E0E0E2;
  width: 94vw;
  height: 300px;
  padding: 20px 20px 10px 20px;  
}
#preview {
  background: #A4C2A8;
  border: 1px solid black;
  padding: 10px;
}
              
            
!

JS

              
                import { marked } from "https://cdn.skypack.dev/marked"
//React:__________________________________________
//Markup Placeholder
const initialContent = `
# This is a heading for my react markdown previer
## Here is a subheading
You can also make [links](https://www.freecodecamp.org)
Inline code can be shown by wrapping it in backticks: \`<p></p>\`
Multiline code requires three backticks:
\`\`\`
<div>
  <h1>This is a header</h1>
</div>
\`\`\`
You can make ordered list with:
1. Ordered list item 1
1. Ordered list item 2
1. Ordered list item 3
Block quotes are easy as well:
> Block Quote
**Bolding** text is always fun
Or add images and logos:
![freeCodeCamp Logo](https://cdn.freecodecamp.org/testable-projects-fcc/images/fcc_secondary.svg)
`

//React Component
class APP extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
      input: initialContent,
    }
    this.handleChange = this.handleChange.bind(this);
  }
  
  handleChange = e => this.setState({
      input: e.target.value});
  
  render() { 
    return (
     <div id='appContainer'>
        <div id='input-container'>
          <textarea id='editor' value={this.state.input} onChange={this.handleChange}/>
        </div>
        <div id='output-container'>
          <div id='preview' dangerouslySetInnerHTML={{__html: marked(this.state.input)}}/>
        </div>
     </div>
    );
  }
};

//Render React
ReactDOM.render(<APP/>, document.getElementById('wrapper'));
              
            
!
999px

Console