What do I need to escape inside the html tag

Question

I use the

 tag in my blog to post code. I know I have to change < to < and > to >         


        

Answer 1

What happens if you use the

 tag to display HTML markup on your blog:




Use a span tag with style attribute to hightlight words




This will pass HTML validation, but does it produce the expected result? No. The correct way is:



Use a <span style="background: yellow;">span tag with style attribute</span> to hightlight words




Another example: if you use the pre tag to display some other language code, the HTML encoding is still required:

if (i && j) return;


This might produce the expected result but does it pass HTML validation? No. The correct way is:

if (i && j) return;


Long story short, HTML-encode the content of a pre tag just the way you do with other tags.