# ArrayIsSeries

The function checks whether an array is a timeseries.

```
bool  ArrayIsSeries(
   const void&  array[]    // checked array
   );

```

Parameters

array[]

[in]  Checked array.

Return Value

It returns true, if a checked array is an array timeseries, otherwise it returns false. Arrays passed as a parameter to the [OnCalculate()](/en/docs/basis/function/events#oncalculate2) function must be checked for the order of accessing the array elements by [ArrayGetAsSeries()](/en/docs/array/arraygetasseries).

Example:

```
#property indicator_chart_window
#property indicator_buffers 1
#property indicator_plots   1
//---- plot Label1
#property indicator_label1  "Label1"
#property indicator_type1   DRAW_LINE
#property indicator_color1  clrRed
#property indicator_style1  STYLE_SOLID
#property indicator_width1  1
//--- indicator buffers
double         Label1Buffer[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
void OnInit()
  {
//--- indicator buffers mapping
   SetIndexBuffer(0,Label1Buffer,INDICATOR_DATA);
//---
  }
//+------------------------------------------------------------------+
//| 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[])
  {
//---
   if(ArrayIsSeries(open))
      Print("open[] is timeseries");
   else
      Print("open[] is not timeseries!!!");
//--- return value of prev_calculated for next call
   return(rates_total);
  }

```

See also

[Access to timeseries and indicators](/en/docs/series)