Background highlight text in a code block?

Question

My goal is to be able to display something like this:

I want to background highlight a piece of code inside a code block that already has syntax highlighting. I want to do this on a markdown file I have on Github that is hosted on Github Pages (can use kramdown markdown, html, css).

I am aware that you can have syntax highlighting inside a code block doing something like this:

```java
int foo (void) {
    int i;
}
```

I am also aware that I can background highlight text inside a code block by doing something like this:

<pre><code>int foo (void) {
    <span style="background-color:yellow">int i;</span>
}
</code></pre>

But how do I combine these two things?

Answer 1

You can use Google's code-prettify to color the code. It will colorize all code with the class prettyprint. Then you can use a <span> tag to set the background color.

pre {
  background-color: #eee;
  border-radius: 5px;
}

<script src="https://cdn.jsdelivr.net/gh/google/code-prettify@master/loader/run_prettify.js"></script>
  <pre>
    <code class="prettyprint">
 int foo (void) {
   <span style="background-color:yellow">int i;</span>
 }
 // Yay code and it has colors
    </code>
  </pre>