格式化输出Json对象

alert(JsonUti.convertToString(jsonObj));  //jsonObj为json对象。

var JsonUti = {
    //定义换行符
    n: "\n",

    //定义制表符
    t: "\t",

    //转换String
    convertToString: function(obj) {
        return JsonUti.__writeObj(obj, 1);
    },

    //写对象
    __writeObj: 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 "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
    },

    __isArray: function(obj) {
        if (obj) {
            return obj.constructor == Array;
        }
        return false;
    },

    __repeatStr: function(str, times) {
        var newStr = [];
        if (times > 0) {
            for (var i = 0; i < times; i++) {
                newStr.push(str);
            }
        }
        return newStr.join("");
    }
};