How to Regex-replace multiple tags with one tag?

Question

I want

to turn into


What\'s the pattern for this with regex?

Note: The


Answer 1

The answer from @FtDRbwLXw6 is great although it does not account for   spaces. We can extend this regex to include that as well:

$html = preg_replace('#(
\s*( )*)+#', '
', $html);