$re = '/<div\b.*?\bdata-id=\"([^"]*)\">([^<]*).*?\/>([^<]*)<div\b.*?\bdata-id=\"([^"]*)\">([^<]*).*/m';
$str = '<div id="tarea" contentEditable="true" class="tarea" autocorrect="false" spellCheck="off">
Hello Says! <div class="tag" data-id="1005">Vedant Terkar</div> , <br />To all <div class="tag" data-id="1006">SO Users</div> :-).
</div>
<!-- This textarea is Usually Hidden -->
<textarea id="opc" rows="5" cols="97">
</textarea>';
$subst = "@['id':'$1','tag':'$2']; , $3@['id':'$4','tag':'$5'];";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php