Json中相同或者重复记录的值相加组成新的Json

//原Json
                        var data = [
                            {"Networking": "WiFi", "count_value": "2000"},
                            {"Networking": "WiFi", "count_value": "2890"},
                            {"Networking": "WiFi", "count_value": "2900"},
                            {"Networking": "CellNetwork", "count_value": "3010"},
                            {"Networking": "CellNetwork", "count_value": "3000"}
                        ];<pre name="code" class="javascript">//现在想要把Networking中都为Wifi和CellNetwork的count_value合并
                        var obj = {};
                        for (var i in data) {
                            if (obj[data[i].Networking]) {
                                obj[data[i].Networking].value = Number(obj[data[i].Networking].value) + Number(data[i].count_value);
                            } else {
                                obj[data[i].Networking] = {
                                    value: data[i].count_value
                                }
                            }
                        }

//结果

console.log(JSON.stringify(obj));

                                              {"WiFi":{"value":7790},"CellNetwork":{"value":6010}}

for (var i in obj) {
    console.log(i);
}                          //结果为：  WiFi  CellNetwork