highlight.js

Using highlight.js

<html lang="en">
<head>
    <meta charset="UTF-8" />
    <title>highlight.js</title>
    <script src="//d3js.org/d3.v4.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.9.1/highlight.min.js"></script>
    <link href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.9.1/styles/default.min.css" rel="stylesheet" />  
    
    <script>hljs.initHighlightingOnLoad();</script>
    <style>
        #code1{ width: 300px;}
    </style>

</head>
<body>
    <div class="container">
        <pre><code class="javascript" id="code1">
             </code>
        </pre>
    </div>

</script>
</body>
</html>

https://d3js.org/d3.v4.min.js

https://cdnjs.cloudflare.com/ajax/libs/highlight.js/8.9.1/highlight.min.js