long or ulong type variable for magic number?

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I don't know weather this is a problem or not. I just don't have enough experience working with class functions to know.

For example CPositionInfo sets Magic as a long.

class CPositionInfo : public CObject
  {
protected:
   ENUM_POSITION_TYPE m_type;
   double            m_volume;
   double            m_price;
   double            m_stop_loss;
   double            m_take_profit;

public:
                     CPositionInfo(void);
                    ~CPositionInfo(void);
   //--- fast access methods to the integer position propertyes
   ulong             Ticket(void) const;
   datetime          Time(void) const;
   ulong             TimeMsc(void) const;
   datetime          TimeUpdate(void) const;
   ulong             TimeUpdateMsc(void) const;
   ENUM_POSITION_TYPE PositionType(void) const;
   string            TypeDescription(void) const;
   long              Magic(void) const;

CTrade RequestMagic specifies that Magic is a ulong.

class CTrade : public CObject
  {
protected:
   MqlTradeRequest   m_request;              // request data
   MqlTradeResult    m_result;               // result data
   MqlTradeCheckResult m_check_result;       // result check data
   bool              m_async_mode;           // trade mode
   ulong             m_magic;                // expert magic number
   ulong             m_deviation;            // deviation default
   ENUM_ORDER_TYPE_FILLING m_type_filling;
   ENUM_ACCOUNT_MARGIN_MODE m_margin_mode;
   //---
   ENUM_LOG_LEVELS   m_log_level;

public:
                     CTrade(void);
                    ~CTrade(void);
   //--- methods of access to protected data
   void              LogLevel(const ENUM_LOG_LEVELS log_level) { m_log_level=log_level; }
   void              Request(MqlTradeRequest &request) const;
   ENUM_TRADE_REQUEST_ACTIONS RequestAction(void)   const { return(m_request.action);       }
   string            RequestActionDescription(void) const;
   ulong             RequestMagic(void)             const { return(m_request.magic);    

Sometimes long is used sometimes ulong is used, it varies across different classes and functions.

Does it make any real difference other than maximum length of the stored number?

Thank you

 
DHess10000: Does it make any real difference other than maximum length of the stored number?

When in doubt, read the documentation. Trade Request Structure - Data Structures - Constants, Enumerations and Structures - MQL5 Reference - Reference on algorithmic/automated trading language for MetaTrader 5 it's ulong.

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