json字符串转换

/*json转成字符串*/
$.jsonToStr = function(obj){
     var THIS = this;
       switch (typeof(obj))
       {
          case 'string':
            return '"'+ obj.replace(/(["\\])/g, '\\$1') + '"';
          case 'array':
            return '[' + obj.map(THIS.jsonToStr).join(',') + ']';
          case 'object':
            if (obj instanceof Array)
            {
               var strArr = [];
               var len = obj.length;
               for (var i = 0; i < len; i++)
               {
                 strArr.push(THIS.jsonToStr(obj[i]));
               }
               return '[' + strArr.join(',') + ']';
            }
            else if(obj==null)
            {
               return 'null';
            }
            else
            {
               var string = [];
               for (var property in obj) string.push(THIS.jsonToStr(property) + ':' + THIS.jsonToStr(obj[property]));
               return '{'+ string.join(',') + '}';
            }
          case 'number':
            return '"' + obj + '"';
          case false:
            return '"' + obj + '"';
       }   
}

/* 字符串转换为 json 对象 */
function str2json(str)
{
   eval("var json_obj = " + str);
   return json_obj;
}