匹配<strong>preg_replace 中的</strong>所有<strong>标签</strong>

Question

We are new to regex (preg_replace) in PHP and are having a little trouble getting it to do exactly what we want.

We have, for example, HTML code like this:

<h2><strong>Automatic Writing</strong> <strong>– A Conduit For An Entity From Another World?</strong></h2>

We want to remove all styling tags inside the H2 (and even match H3/H4/H5 tags too).

We have constructed the following code so far (we are integrating with Wordpress):

function removebolding($content)
        {
            $content =
                preg_replace('/(<h([1-6])[^>]*>)\s?<strong>(.*)?<\/strong>\s?(<\/h\2>)/', "$1$3$4", $content);
            return $content;
        }

        add_filter('the_content', 'removebolding');

This does work, however, it only removes the first 'strong' tag - we are left with:

<h2>Automatic Writing <strong>– A Conduit For An Entity From Another World?</strong></h2>

How can we match/remove all 'strong' tags? Also, perhaps we could simply extract the contents of the heading tags, run a strip_tags function and then replace with the output?

Any help, suggestions, and code samples are gratefully appreciated in advance.

Many thanks.

Answer 1

You may use

preg_replace_callback('~<h([1-6])>.*?</h\1>~is', function($m) { 
    return preg_replace('~</?strong>~i', '', $m[0]); }
, $s)

Output: <h2>Automatic Writing – A Conduit For An Entity From Another World?</h2>

The regex performance may be enhanced like this:

'~<h([1-6])>[^<]*(?:<(?!/h\1>[^<]*)*</h\1>~i'

See the PHP demo .

• ~<h([1-6])>.*?</h\\1>~s matches any h tags, with any text in between them
• preg_replace('~</?strong>~i', '', $m[0]) removes all <strong> and </strong> tags only in the main regex match value, in $m[0] .