1.把html元素全部去掉，或者保留某几个html标签
<?php
$text = '<p>Test paragraph.</p><!-- Comment --> <a href="#fragment">Other text</a>';
echo strip_tags($text);
echo "/n";
// Allow <p> and <a>
echo strip_tags($text, '<p><a>');
?>
结果为(去掉了注释)：
<blockquote>Test paragraph. Other text
<p>Test paragraph.</p> <a href="#fragment">Other text</a></blockquote>2.相反，只去掉某一个html标签
<?php
function strip_only($str, $tags, $stripContent = false) {
$content = '';
if(!is_array($tags)) {
$tags = (strpos($str, '>') !== false ? explode('>', str_replace('<', '', $tags)) : array($tags));
if(end($tags) == '') array_pop($tags);
}
foreach($tags as $tag) {
if ($stripContent)
$content = '(.+</'.$tag.'[^>]*>|)';
$str = preg_replace('#</?'.$tag.'[^>]*>'.$content.'#is', '', $str);
}
return $str;
}
$str = '<font color="red">red</font> text';
$tags = 'font';
$a = strip_only($str, $tags); // red text
$b = strip_only($str, $tags, true); // text
?>
