SO - 16995467

by Arun P Johny

HTML

<div class="post">
 [tag]dfghf[/tag][tag]gh[/tag][tag]cxbcvb[/tag][tag]gh[/tag][tag]cxbcvb[/tag][tag]gh[/tag]ddd
 </div>

CSS

span {
    color: red;
}

JavaScript

$('.post').html(function(){
    return $(this)
    .html()
    .replace(/\[tag\]/g,'<span class="tag">')
    .replace(/\[\/tag\]/g,'</span>')
})