php正则替换标签的实现方法：首先通过“strip_tags”函数剥去字符串中的HTML标签；然后利用正则表达式替换标签，代码语句如“pregreplace("/s+/","",str=pregreplace("/s+/","")”。
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1.strip_tags(剥去字符串中的 HTML 标签)
strip_tags() 函数剥去字符串中的 HTML、XML 以及 PHP 的标签。
2.字符串替换
str_replace(array(“ ”,” ”,””,”
”,””,”
”),array(“”,”“,”“,”“,”“,”“)
3.利用正则表达式(效率稍微低一些)
str=pregreplace("/s+/","",str); //过滤多余回车
str=pregreplace("/
str=pregreplace("//si","",str); //注释
str=pregreplace("//si","",str); //过滤DOCTYPE
str=pregreplace("//si","",str); //过滤html标签
str=pregreplace("//si","",str); //过滤head标签
str=pregreplace("//si","",str); //过滤meta标签
str=pregreplace("//si","",str); //过滤body标签
str=pregreplace("//si","",str); //过滤link标签
str=pregreplace("//si","",str); //过滤form标签
str=pregreplace("/cookie/si","COOKIE",str); //过滤COOKIE标签
str=pregreplace("/(.∗?)/si","",str); //过滤applet标签
str=pregreplace("//si","",str); //过滤applet标签
str=pregreplace("/(.∗?)/si","",str); //过滤style标签
str=pregreplace("//si","",str); //过滤style标签
str=pregreplace("/(.∗?)/si","",str); //过滤title标签
str=pregreplace("//si","",str); //过滤title标签
str=pregreplace("/(.∗?)/si","",str); //过滤object标签
str=pregreplace("//si","",str); //过滤object标签
str=pregreplace("/(.∗?)/si","",str); //过滤noframes标签
str=pregreplace("//si","",str); //过滤noframes标签
str=pregreplace("/(.∗?)/si","",str); //过滤frame标签
str=pregreplace("//si","",str); //过滤frame标签
str=pregreplace("/(.∗?)/si","",str); //过滤script标签
str=pregreplace("//si","",str); //过滤script标签
str=pregreplace("/javascript/si","Javascript",str); //过滤script标签
str=pregreplace("/vbscript/si","Vbscript",str); //过滤script标签
str=pregreplace("/on([a−z]+)s∗=/si","On1=",str); //过滤script标签
str=preg_replace("//si","&＃",str); //过滤script标签，如javAsCript:alert(
str=pregreplace("//si","",str);//匹配任意html标签方式
this−>content=pregreplace("//si","",this->content);//过滤大多数的html标签
