doEncode = function(o){
            if(typeof o == "undefined" || o === null){
                return "null";
            }else if(Ext.isArray(o)){
                return encodeArray(o);
            }else if(Object.prototype.toString.apply(o) === '[object Date]'){
                return Ext.util.JSON.encodeDate(o);
            }else if(typeof o == "string"){
                return encodeString(o);
            }else if(typeof o == "number"){
                return isFinite(o) ? String(o) : "null";
            }else if(typeof o == "boolean"){
                return String(o);
            }else {
                var a = ["{"], b, i, v;
                for (i in o) {
                    if(!useHasOwn || o.hasOwnProperty(i)) {
                        v = o[i];
                        switch (typeof v) {
                        case "undefined":
                        case "function":
                        case "unknown":
                            break;
                        default:
                            if(b){
                                a.push(',');
                            }
                            a.push(doEncode(i), ":",
                                    v === null ? "null" : doEncode(v));
                            b = true;
                        }
                    }
                }
                a.push("}");
                return a.join("");
            }    
        }

?Ext.util.JSON.decode?? Ext.decode???? json字符串解码成js对象，js中直接调eval方法就可以

Ext.util.JSON.encode?? Ext.encode???? js对象编码成json字符串，代码如下

?

?