所以这里的html就是html标签，这样的写法属于php原生语法
没有使用框架和模板引擎就是这样，模板引擎其实就是把模板引擎的标签转换成这样的原生语法再执行。
理论上来说原生语法是最快的，但是因为不利于修改优化和维护，而框架在牺牲了一小部分性能的时候解决了这个问题，所以框架会火起来
php正则过滤html标签、空格、换行符的代码$str=preg_replace("/\s+/", " ", $str)
//过滤多余回车
$str=preg_replace("/<[ ]+/si","<",$str)
//过滤<__("<"号后面带空格)
$str=preg_replace("/<\!--.*?-->/si","",$str)
//注释
$str=preg_replace("/<(\!.*?)>/si","",$str)
//过滤DOCTYPE
$str=preg_replace("/<(\/?html.*?)>/si","",$str)
//过滤html标签
$str=preg_replace("/<(\/?head.*?)>/si","",$str)
//过滤head标签
$str=preg_replace("/<(\/?meta.*?)>/si","",$str)
//过滤meta标签
$str=preg_replace("/<(\/?body.*?)>/si","",$str)
//过滤body标签
$str=preg_replace("/<(\/?link.*?)>/si","",$str)
//过滤link标签
$str=preg_replace("/<(\/?form.*?)>/si","",$str)
//过滤form标签
$str=preg_replace("/cookie/si","COOKIE",$str)
//过滤COOKIE标签
$str=preg_replace("/<(applet.*?)>(.*?)<(\/applet.*?)>/si","",$str)
//过滤applet标签
$str=preg_replace("/<(\/?applet.*?)>/si","",$str)
//过滤applet标签
$str=preg_replace("/<(style.*?)>(.*?)<(\/style.*?)>/si","",$str)
//过滤style标签
$str=preg_replace("/<(\/?style.*?)>/si","",$str)
//过滤style标签
$str=preg_replace("/<(title.*?)>(.*?)<(\/title.*?)>/si","",$str)
//过滤title标签
$str=preg_replace("/<(\/?title.*?)>/si","",$str)
//过滤title标签
$str=preg_replace("/<(object.*?)>(.*?)<(\/object.*?)>/si","",$str)
//过滤object标签
$str=preg_replace("/<(\/?objec.*?)>/si","",$str)
//过滤object标签
$str=preg_replace("/<(noframes.*?)>(.*?)<(\/noframes.*?)>/si","",$str)
//过滤noframes标签
$str=preg_replace("/<(\/?noframes.*?)>/si","",$str)
//过滤noframes标签
$str=preg_replace("/<(i?frame.*?)>(.*?)<(\/i?frame.*?)>/si","",$str)
//过滤frame标签
$str=preg_replace("/<(\/?i?frame.*?)>/si","",$str)
//过滤frame标签
$str=preg_replace("/<(script.*?)>(.*?)<(\/script.*?)>/si","",$str)
//过滤script标签
$str=preg_replace("/<(\/?script.*?)>/si","",$str)
//过滤script标签
$str=preg_replace("/javascript/si","Javascript",$str)
//过滤script标签
$str=preg_replace("/vbscript/si","Vbscript",$str)
//过滤script标签
$str=preg_replace("/on([a-z]+)\s*=/si","On\\1=",$str)
//过滤script标签
$str=preg_replace("/
