两种思路，一种是列出需要用到的转义项，通过正则来转化；另一种通过转化为html语言，通过浏览器帮助我们翻译，然后获取innerText

var HtmlUtil = {/*1.用浏览器内部转换器实现html编码（转义）*/htmlEncode:function (html){//1.首先动态创建一个容器标签元素，如DIVvar temp = document.createElement ("div");//2.然后将要转换的字符串设置为这个元素的innerText或者textContent(temp.textContent != undefined ) ? (temp.textContent = html) : (temp.innerText = html);//3.最后返回这个元素的innerHTML，即得到经过HTML编码转换的字符串了var output = temp.innerHTML;temp = null;return output;},/*2.用浏览器内部转换器实现html解码（反转义）*/htmlDecode:function (text){//1.首先动态创建一个容器标签元素，如DIVvar temp = document.createElement("div");//2.然后将要转换的字符串设置为这个元素的innerHTML(ie，火狐，google都支持)temp.innerHTML = text;//3.最后返回这个元素的innerText或者textContent，即得到经过HTML解码的字符串了。var output = temp.innerText || temp.textContent;temp = null;return output;},/*3.用正则表达式实现html编码（转义）*/htmlEncodeByRegExp:function (str){var temp = "";if(str.length == 0) return "";temp = str.replace(/&/g,"&");temp = temp.replace(/</g,"<");temp = temp.replace(/>/g,">");temp = temp.replace(/\s/g," ");temp = temp.replace(/\'/g,"'");temp = temp.replace(/\"/g,""");return temp;},/*4.用正则表达式实现html解码（反转义）*/htmlDecodeByRegExp:function (str){var temp = "";if(str.length == 0) return "";temp = str.replace(/&/g,"&");temp = temp.replace(/</g,"<");temp = temp.replace(/>/g,">");temp = temp.replace(/ /g," ");temp = temp.replace(/'/g,"\'");temp = temp.replace(/"/g,"\"");return temp;},/*5.用正则表达式实现html编码（转义）（另一种写法）*/html2Escape:function(sHtml) {return sHtml.replace(/[<>&"]/g,function(c){return {'<':'<','>':'>','&':'&','"':'"'}[c];});},/*6.用正则表达式实现html解码（反转义）（另一种写法）*/escape2Html:function (str) {var arrEntities={'lt':'<','gt':'>','nbsp':' ','amp':'&','quot':'"'};return str.replace(/&(lt|gt|nbsp|amp|quot);/ig,function(all,t){return arrEntities[t];});}};