js 转义

function html_decode(str) 
{ 
    var s = ""; 
    if (str.length == 0) return ""; 
    s = str.replace(/&/g, "&"); 
    s = s.replace(/&lt;/g, "<"); 
    s = s.replace(/&gt;/g, ">"); 
    s = s.replace(/&nbsp;/g, " "); 
    s = s.replace(/'/g, "\‘"); 
    s = s.replace(/&quot;/g, "\""); 
    s = s.replace(/<br\/>/g, "\n"); 
    return s; 
}

function removeHtmlTab(tab) {
 return tab.replace(/<[^<>]+?>/g,‘‘);//删除所有HTML标签
}
function html2Escape(sHtml) {
 return sHtml.replace(/[<>&"]/g,function(c){return {‘<‘:‘<‘,‘>‘:‘>‘,‘&‘:‘&‘,‘"‘:‘"‘}[c];});
}

function escape2Html(str) {
 var arrEntities={‘lt‘:‘<‘,‘gt‘:‘>‘,‘nbsp‘:‘ ‘,‘amp‘:‘&‘,‘quot‘:‘"‘};
 return str.replace(/&(lt|gt|nbsp|amp|quot);/ig,function(all,t){return arrEntities[t];});
}
function nbsp2Space(str) {
 var arrEntities = {‘nbsp‘ : ‘ ‘};
 return str.replace(/&(nbsp);/ig, function(all, t){return arrEntities[t]})
}
function return2Br(str) {
 return str.replace(/\r?\n/g,"<br />");
}
function trimBr(str) {
 str=str.replace(/((\s| )*\r?\n){3,}/g,"\r\n\r\n");//限制最多2次换行
 str=str.replace(/^((\s| )*\r?\n)+/g,‘‘);//清除开头换行
 str=str.replace(/((\s| )*\r?\n)+$/g,‘‘);//清除结尾换行
 return str;
}
function mergeSpace(str) {
 str=str.replace(/(\s| )+/g,‘ ‘);
 return str;
}

var str="<script type=‘text/javascript‘ >jjj</script>kkk " ;str=str.replace(/</g,‘<‘);
str=str.replace(/>/g,‘>‘);
var reg=/<script[^>]*>(.|\n)*?(?=<\/script>)<\/script>/gi;
alert(str.replace(reg,‘‘));