<div>
Add in capturing parens around the thing being sought, then use the appropriate backreference (most likely 1) to refer to what was captured by the parens.<br />
<br />
e.g.<br />
<br />

<pre><code class="code-1 nolinks" id="code-20-40453578-1"><span>$display_html = (</span>
<span>   &quot;/(&quot;.$search_string.&quot;)/i&quot;, </span>
<span>   &quot;&lt;b class='highlight'&gt;$1&lt;/b&gt;&quot;,</span>
<span>    $row['title'] );</span>
</code></pre>
<br />
Because I have only used one set of capturing parens, the backreference I use is for group 1 (that's the $1 bit in the replacement).
</div>


<div>
thanks for the detailed help!
</div>


<div>
<div class="content wysiwyg-content">
the following statement works:<br />
<br />
$display_html = <br />
preg_replace(<br />
&nbsp; &nbsp;&quot;/&quot;.$search_string.&quot;/i&quot;, <br />
&nbsp; &nbsp;&quot;&lt;b class='highlight'&gt;&quot;.$searc<wbr />h_string.&quot;<wbr />&lt;/b&gt;&quot;,<br />
&nbsp; &nbsp; $row['title'] );<br />
<br />
where search_string is what is being searched for, and 'title'<br />
is the &nbsp;LIKE-matching result from a mysql database.<br />
<br />
currently the regex substitutes the CASE that was used as typed in by the searcher.<br />
I would like to have the CASE retained to that of what the field was in the database<br />
(could be lower, initial cap, all caps, etc.)<br />
<br />
how can the regex substitution (which surrounds the title search phrase with HTML tags for highlighting)<br />
be altered to retain the the capitalization in the returned field result.
</div>
</div>


the following statement works:

$display_html = 
preg_replace(
   "/".$search_string."/i", 
   "<b class='highlight'>".$search_string."</b>",
    $row['title'] );

where search_string is what is being searched for, and 'title'
is the  LIKE-matching result from a mysql database.

currently the regex substitutes the CASE that was used as typed in by the searcher.
I would like to have the CASE retained to that of what the field was in the database
(could be lower, initial cap, all caps, etc.)

how can the regex substitution (which surrounds the title search phrase with HTML tags for highlighting)
be altered to retain the the capitalization in the returned field result.

PHP regex    how to  replace with the same string

PHP is a widely-used server-side scripting language especially suited for web development, powering tens of millions of sites from Facebook to personal WordPress blogs. PHP is often paired with the MySQL relational database, but includes support for most other mainstream databases. By utilizing different Server APIs, PHP can work on many different web servers as a server-side scripting language.