MQL4参考标准常量，列举和架构命名常量 预定义大量代替值

Predefined Macro Substitutions

To simplify the debugging process and obtain information about operation of a mql4-program, there are special macro constant, values of which are set at the moment of compilation. The easiest way to use these constants is outputting values by the Print() function, as it's shown in the example.

Constant	Description
__DATE__	File compilation date without time (hours, minutes and seconds are equal to 0)
__DATETIME__	File compilation date and time
__LINE__	Line number in the source code, in which the macro is located
__FILE__	Name of the currently compiled file
__PATH__	An absolute path to the file that is currently being compiled
__FUNCTION__	Name of the function, in whose body the macro is located
__FUNCSIG__	Signature of the function in whose body the macro is located. Logging of the full description of functions can be useful in the identification of overloaded functions
__MQLBUILD__, __MQL4BUILD__	Compiler build number

Example:

#property copyright "Copyright © 2009, MetaQuotes Software Corp."
#property link      "https://www.metaquotes.net"
//+------------------------------------------------------------------+
//| Expert initialization function                                   |
//+------------------------------------------------------------------+
void OnInit()
  {
//--- an example of information output at Expert Advisor initialization
   Print(" __FUNCTION__ = ",__FUNCTION__,"  __LINE__ = ",__LINE__);
//--- set the interval between the timer events
   EventSetTimer(5);
//---
  }
//+------------------------------------------------------------------+
//| Expert deinitialization function                                 |
//+------------------------------------------------------------------+
void OnDeinit(const int reason)
  {
//--- an example of information output at Expert Advisor deinitialization
   Print(" __FUNCTION__ = ",__FUNCTION__,"  __LINE__ = ",__LINE__);
//---
  }
//+------------------------------------------------------------------+
//| Expert tick function                                             |
//+------------------------------------------------------------------+
void OnTick()
  {
//--- information output at tick receipt
   Print(" __MQLBUILD__ = ",__MQLBUILD__,"  __FILE__ = ",__FILE__);
   Print(" __FUNCTION__ = ",__FUNCTION__,"  __LINE__ = ",__LINE__);
   test1(__FUNCTION__);
   test2();
//---
  }
//+------------------------------------------------------------------+
//| test1                                                            |
//+------------------------------------------------------------------+
void test1(string par)
  {
//--- information output inside the function
   Print(" __FUNCTION__ = ",__FUNCTION__,"  __LINE__ = ",__LINE__," par = ",par);
  }
//+------------------------------------------------------------------+
//| test2                                                            |
//+------------------------------------------------------------------+
void test2()
  {
//--- information output inside the function
   Print(" __FUNCTION__ = ",__FUNCTION__,"  __LINE__ = ",__LINE__);
  }
//+------------------------------------------------------------------+
//| OnTimer event handler                                            |
//+------------------------------------------------------------------+
void OnTimer()
  {
//---
   Print(" __FUNCTION__ = ",__FUNCTION__,"  __LINE__ = ",__LINE__);
   test1(__FUNCTION__);
  }
//+------------------------------------------------------------------+

命名常量数学常量