Save struct indexed name as a variable

This may sound Weird, Yet I need to save a struct index string as a variable. reason:The struct is formed as a query request for stock values - and in order to draw a valid graph the date is needed - the Date is the name of the struct Struct:

      % code
  end
stock.TimeSeries_Daily_  
% Within 
 stock.TimeSeries_Daily_ 
 % the struct continues as:
stock.TimeSeries_Daily_.x2017_12_01,
 stock.TimeSeries_Daily_.x2017_11_30,
 stock.TimeSeries_Daily_.x2017_11_29,
 stock.TimeSeries_Daily_.x2017_11_28,
 stock.TimeSeries_Daily_.x2017_11_27
and so on

Within final struct I get the needed value

Yet I need a variable to hold:

if true
  % code
end
2017_11_30
2017_11_29
2017_11_28
and so on..

meaning I need to save the "name" of the struct into a different varible

How do I do this??

Thank you in Advance

[Stephen23]

This is rather awkward. Just use indexing, and store the date as data in its own right:

stock.TimeSeries_Daily(1).date = ...
stock.TimeSeries_Daily(2).date = ...

Or put the dates into one array. Why do you need to put the meta-data into the fieldnames?

[Daniel Grebler]

The Data is sent that way from webread function. The date represent an open market day so I cant "choose" my own dates (due to historical events - holiday weekends and crises)

Answer 1

[Jos (10584)]

You can use FIELDNAMES:

FN = fieldnames(stock.TimeSeries_Daily_)
% process these names in more common date formats using datenum and datestr
num = datenum(FN,'xyyyy_mm_dd')
str = datestr(num,'yyyymmdd')

[Daniel Grebler]

Exactly what I needed! Thank you

Answer 2

[Steven Lord]

Are you required to store your data in this format? If you're using release R2016b or later I recommend using a timetable array instead. If you do store your data in a timetable named TT, you can access the list of times using:

TT.Properties.RowTimes