用正则表达式进行转换处理
使用正则表达式也是一种常用的处理方式，实现原理就是使用替换的方式来实现转码和解码，转码时把<>，空格符，&，’，""替换成html编码，解码就把html编码替换成对应的字符，实现代码如下：
var HtmlUtil = {
/1.用正则表达式实现html转码/
htmlEncodeByRegExp:function (str){
var s = “”;
if(str.length == 0) return “”;
s = str.replace(/&/g,"&");
s = s.replace(/</g,"<");
s = s.replace(/>/g,">");
s = s.replace(/ /g," “);
s = s.replace(/’/g,”’");
s = s.replace(/"/g,""");
return s;
},
/2.用正则表达式实现html解码/
htmlDecodeByRegExp:function (str){
var s = “”;
if(str.length == 0) return “”;
s = str.replace(/&/g,"&");
s = s.replace(/</g,"<");
s = s.replace(/>/g,">");
s = s.replace(/ /g," “);
s = s.replace(/’/g,”’");
s = s.replace(/"/g,""");
return s;
}