如何让我的价格向量 = 我的 json 数组中的值

Question

Hello I am pretty new to json parsing and parsing in general so I am wondering what is the best way I can assaign the correct values for the price of the underlying stock I am looking at. Below is an example of the code I am working with and comments next to them showing kinda what Im confused about

Json::Value chartData = IEX::stocks::chart(symbolSearched);
int n = 390;
QVector<double> time(n), price(n);

//Time and Date Setup
QDateTime start = QDateTime(QDate::currentDate());
QDateTime local = QDateTime::currentDateTime();
QDateTime UTC(local);
start.setTimeSpec(Qt::UTC);
double startTime = start.toTime_t();
double binSize = 3600*24;
time[0] = startTime;
price[0] = //First market price of the stock at market open (930AM)
for(int i = 0; i < n; i++)  
{
    time[i] = startTime + 3600*i;
    price[i] = //Stores prices of specific company stock price all the way until 4:30PM(Market close)
}

the charData is the json output with all the data,

.

I am wondering how I can get the various values inside the json and store them, and also since its intraday data how can I get it where it doesnt store p[i] if there is no data yet due to it being early in the day, and what is the best way to update this every minute so it continously reads in real time data?

Answer 1

Hope I understood correctly (correct me if not) and you just want to save some subset of json data to your QVector . Just iterate through all json elements:

for (int idx = 0; index < chartData.size(); ++idx) {
  time[idx] = convert2Timestamp(chartData[idx]["minute"]);
  price[idx] = convert2Price(chartData[idx]["high"], chartData[idx]["low"],
    chartData[idx]["open"], chartData[idx]["close"], chartData[idx]["average"]);
}

Then you should define what is the logic of convert2Timestamp (how would you like to store the time information) and the logic of convert2Price - how would you like to store the price info, only highest/lowest, only the closing value, maybe all of these numbers grouped together in a structure/class.

Then if you want to execute similar logic every minute to update your locally recorded data, maybe instead of price[idx] = /* something */ you should push additional items that are new to your vector.

If there is a possibility that some of the json keys might not exist, in JsonCPP you could provide a default value eg elem.get(KEY, DEFAULT_VAL) .