docs: function (obj    //对象
          , level             //层次（基数为1）
          , isInArray) {       //此对象是否在一个集合内
          //如果为空，直接输出null
          if (obj == null) {
              return JSON.stringify("null");
          }
          //为普通类型，直接输出值
          if (obj.constructor == Number || obj.constructor == Date || obj.constructor == String || obj.constructor == Boolean) {
              var v = obj.toString();
              var tab = isInArray ? JsonUti.__repeatStr(JsonUti.t, level - 1) : "";
              if (obj.constructor == String || obj.constructor == Date) {
                  //时间格式化只是单纯输出字符串，而不是Date对象
                  return tab + ("\"" + v + "\"");
              }
              else if (obj.constructor == Boolean) {
                  return tab + v.toLowerCase();
              }
              else {
                  return tab + (v);
              }
          }
  
          //写Json对象，缓存字符串
          var currentObjStrings = [];
          //遍历属性
          for (var name in obj) {
              var temp = [];
              //格式化Tab
              var paddingTab = JsonUti.__repeatStr(JsonUti.t, level);
              temp.push(paddingTab);
              //写出属性名
              temp.push(name + " : ");
  
              var val = obj[name];
              if (val == null) {
                  temp.push("null");
              }
              else {
                  var c = val.constructor;
  
                  if (c == Array) { //如果为集合，循环内部对象
                      temp.push(JsonUti.n + paddingTab + "[" + JsonUti.n);
                      var levelUp = level + 2;    //层级+2
  
                      var tempArrValue = [];      //集合元素相关字符串缓存片段
                      for (var i = 0; i < val.length; i++) {
                          //递归写对象
                          tempArrValue.push(JsonUti.__writeObj(val[i], levelUp, true));
                      }
  
                      temp.push(tempArrValue.join("," + JsonUti.n));
                      temp.push(JsonUti.n + paddingTab + "]");
                  }
                  else if (c == Function) {
                      temp.push("[Function]");
                  }
                  else {
                      //递归写对象
                      temp.push(JsonUti.__writeObj(val, level + 1));
                  }
              }
              //加入当前对象“属性”字符串
              currentObjStrings.push(temp.join(""));
          }
          return (level > 1 && !isInArray ? JsonUti.n : "")                       //如果Json对象是内部，就要换行格式化
              + JsonUti.__repeatStr(JsonUti.t, level - 1) + "{" + JsonUti.n     //加层次Tab格式化
              + currentObjStrings.join("," + JsonUti.n)                       //串联所有属性值
              + JsonUti.n + JsonUti.__repeatStr(JsonUti.t, level - 1) + "}";   //封闭对象
      }