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
}
}
}

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

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

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