javascript对HTML字符转义与反转义

<script>var HtmlUtil = {    /*1.用浏览器内部转换器实现html转码*/    htmlEncode:function (html){      //1.首先动态创建一个容器标签元素，如DIV      var temp = document.createElement ("div");      //2.然后将要转换的字符串设置为这个元素的innerText(ie支持)或者textContent(火狐，google支持)      (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*/    htmlDecode:function (text){      //1.首先动态创建一个容器标签元素，如DIV      var 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(ie支持)或者textContent(火狐，google支持)，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;     },    /*4.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;     }  };</script> 

var value = document.getElementById('input').value.trim();    //对用户输入进行转义    value = value.replace(/&/g,"&");    value = value.replace(/</g,"<");    value = value.replace(/>/g,">");    value = value.replace(/ /g," ");    value = value.replace(/"/g,'"');

var value = e.target.innerText;     // value = decodeURIComponent(value);     value = value.replace(/&/g,"&");     value = value.replace(/</g,"<");     value = value.replace(/>/g,">");     value = value.replace(/ /g," ");     value = value.replace(/"/g,"'");