MQL4 Reference Array Functions ArraySetAsSeries


The function sets the AS_SERIES flag to a selected object of a dynamic array, and elements will be indexed like in timeseries.

bool  ArraySetAsSeries(
   const void&  array[],    // array by reference
   bool         flag        // true denotes reverse order of indexing



[in][out]  Numeric array to set.


[in]  Array indexing direction.

Return Value

The function returns true on success, otherwise  - false.


The AS_SERIES flag can't be set for multi-dimensional arrays or static arrays (arrays, whose size in square brackets is preset already on the compilation stage). Indexing in timeseries differs from a common array in that the elements of timeseries are indexed from the end towards the beginning (from the newest to oldest data).

Example: Indicator that shows bar number

Indicator for showing bar number


#property indicator_chart_window
#property indicator_buffers 1
//--- indicator buffers
double         NumerationBuffer[];
//| Custom indicator initialization function                         |
int OnInit()
//--- indicator buffers mapping
//--- set buffer style
//--- set indexing for the buffer like in timeseries
//--- set accuracy of showing in DataWindow
//--- how the name of the indicator arry is displayed in DataWindow
   IndicatorShortName("Bar #"); 
//| Custom indicator iteration function                              |
int OnCalculate(const int rates_total,
                const int prev_calculated,
                const datetime &time[],
                const double &open[],
                const double &high[],
                const double &low[],
                const double &close[],
                const long &tick_volume[],
                const long &volume[],
                const int &spread[])
//---  we'll store the time of the current zero bar opening
   static datetime currentBarTimeOpen=0;
//--- revert access to array time[] - do it like in timeseries
//--- If time of zero bar differs from the stored one
     //--- enumerate all bars from the current to the chart depth
      for(int i=rates_total-1;i>=0;i--) NumerationBuffer[i]=i;
//--- return value of prev_calculated for next call

See also

Access to timeseries, ArrayGetAsSeries