If you want to display HTML code syntax, without your browser interpreting it as real markup (and render it) you need to escape reserved HTML characters first.
Look at the <h1> tag inside the <code></code> element below:
<p>You should only use one <code><h1></code> element per article.</p>If you add the code above to an HTML document, the <h1> be interpreted as real mark up, which you obviously don’t want.
You need to escape the angle brackets < and > that surround h1 because they are reserved HTML characters.
Fortunately, it’s easy:
- Replace 
<with < - Replace 
>with > 
Example:
<p>You should only use one <code><h1></code> element per article.</p>Now the code above will render correctly:
You should only use one <h1> element per article.
Now let’s escape some HTML code with a class attribute, e.g.: <p class="lead-paragraph"></p>.
- Replace 
<with < - Replace 
>with > - Replace 
"with " 
Escaped HTML:
<p class="lead-paragraph"></p>