MQL5 ReferenceConversion FunctionsStructToCharArray

StructToCharArray

Copy POD structure to uchar type array.

bool  StructToCharArray(
   const void&  struct_object,     // structure
   uchar&       char_array[],      // array
   uint         start_pos=0        // starting position in the array
   );

Parameters

struct_object

[in] Reference to any type of POD structure (containing only simple data types).

char_array[]

[in] uchar type array.

start_pos=0

[in] Position in the array, starting from which the copied data are added.

Return Value

Returns true if successful, otherwise false.

Note

When copying, the dynamic array automatically expands (ArrayResize) if there is not enough space. If the array cannot be expanded up to the required value, the function returns an error.

Example:

uchar    ExtCharArray[];
MqlRates ExtRates[1];

//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
//--- copy the data of one current bar into the MqlRates structure
   if(CopyRates(Symbol(), PERIOD_CURRENT, 0, 1, ExtRates)!=1)
     {
      Print("CopyRates() failed. Error code: ", GetLastError());
      return;
     }

//--- print the data received in the MqlRates structure in the journal
   Print("Data in the structure immediately after receiving it:");
   MqlRatesPrint(ExtRates[0]);

//--- copy the structure to the uchar type array
   ResetLastError();
   if(!StructToCharArray(ExtRates[0], ExtCharArray))
     {
      Print("StructToCharArray() failed. Error code: ", GetLastError());
      return;
     }

//--- clear the structure
   ZeroMemory(ExtRates[0]);
//--- print the data in the structure after clearing
   Print("\nData in the structure after ZeroMemory():");
   MqlRatesPrint(ExtRates[0]);

//--- now copy the data from the uchar array to the MqlRates structure
   if(!CharArrayToStruct(ExtRates[0], ExtCharArray))
     {
      Print("CharArrayToStruct() failed. Error code: ", GetLastError());
      return;
     }
//--- print the data in the MqlRates structure after copying it from the uchar array
   Print("\nData in the MqlRates structure after copying it from a uchar array:");
   MqlRatesPrint(ExtRates[0]);

   /*
   result:

   Data in the structure immediately after receiving it:
   MqlRates data:
    Time = 2024.02.21 07:00;
    Open = 1.08143;
    High = 1.08158;
    Low = 1.08122;
    Close = 1.08137;
    Tick volume = 1341;
    Spread = 4;
    Real volume = 0

   Data in the structure after ZeroMemory():
   MqlRates data:
    Time = 0;
    Open = 0.00000;
    High = 0.00000;
    Low = 0.00000;
    Close = 0.00000;
    Tick volume = 0;
    Spread = 0;
    Real volume = 0

   Data in the MqlRates structure after copying it from a uchar array:
   MqlRates data:
    Time = 2024.02.21 07:00;
    Open = 1.08143;
    High = 1.08158;
    Low = 1.08122;
    Close = 1.08137;
    Tick volume = 1341;
    Spread = 4;
    Real volume = 0
   */
  }
//+------------------------------------------------------------------+
//| Print the fields of the MqlRates structure in the journal        |
//+------------------------------------------------------------------+
void MqlRatesPrint(MqlRates &rates)
  {
//--- create the output string
   string text=StringFormat(" Time = %s;\n"
                            " Open = %.*f;\n"
                            " High = %.*f;\n"
                            " Low = %.*f;\n"
                            " Close = %.*f;\n"
                            " Tick volume = %I64u;\n"
                            " Spread = %d;\n"
                            " Real volume = %I64u",
                            TimeToString(rates.time),
                            _Digits, rates.open,
                            _Digits, rates.high,
                            _Digits, rates.low,
                            _Digits, rates.close,
                            rates.tick_volume,
                            rates.spread,
                            rates.real_volume);
//--- print the header and the output string in the journal
   Print("MqlRates data:\n", text);
  }