Discussion of article "Migrating from MQL4 to MQL5" - page 5

[Jinsong Zhang]

How about OrderMagicNumber() ? Thanks

[Rashid Umarov]

song_song:

How about OrderMagicNumber() ? Thanks

See  ORDER_MAGIC

[Jinsong Zhang]

iBarShift() is easy to use but iBarShiftMQL4() is quite complex. And so on...

[Cym Act]

Why both "TickValue() and SymbolInfoDouble(_Symbol,SYMBOL_TRADE_TICK_VALUE)" always return "0"?!

[wangdaqing]

Hi, Rosh:

    I am very appreciated you said that:" I have plans to develop the MQL4 emulator, which will allow you to run your MQL4 programs in new MetaTrader 5 client terminal."

I am not a good programme designer but a trader. MQL5 is too difficult for me. 

    Waiting for your MQL4 emulator. TKS a Million!

    Best  Wishes for you.     

[[Deleted]]

I found a mistake 

If only one chart window is open. Then the ID of this window of  =  -1 

int WindowHandleMQL4(string symbol,
                     int tf)
  {
   ENUM_TIMEFRAMES timeframe=TFMigrate(tf);
   long currChart,prevChart=ChartFirst();
   int i=0,limit=100;
   while(i<limit)
     {
      currChart=ChartNext(prevChart);
      if(currChart<0) break; 
      if(ChartSymbol(currChart)==symbol
         && ChartPeriod(currChart)==timeframe)
         return((int)currChart);
      prevChart=currChart;
      i++;
     }
   return(0);
  }

-

int WindowHandleMQL4(string symbol,
                     int tf)
  {
   ENUM_TIMEFRAMES timeframe=TFMigrate(tf);
   long currChart,prevChart=ChartFirst();
   int i=0,limit=100;
   while(i<limit)
     {
      currChart=ChartNext(prevChart);
        
      if( currChart<0 && currChart != -1) break;
        
      if(ChartSymbol(currChart)==symbol
        && ChartPeriod(currChart)==timeframe)
         
         return((int)currChart);
      prevChart=currChart;
      i++;
     }
   return(0);
  }

[williamwong]

Also be careful on the precedence.  I spent half a day debugging a logic and found that the precedence of && and || are different between MQL4 (|| first) and MQL5 (&& first).  So in migrating from MQL4 to MQL5, make sure you search through all the comparison expressions.

[Rashid Umarov]

williamwong:

Also be careful on the precedence.  I spent half a day debugging a logic and found that the precedence of && and || are different between MQL4 (|| first) and MQL5 (&& first).  So in migrating from MQL4 to MQL5, make sure you search through all the comparison expressions.

You are right. See Precedence Rules:

Each group of operations in the table has the same priority. The higher the priority of operations is, the higher it is position of the group in the table. The precedence rules determine the grouping of operations and operands.

Attention: Precedence of operations in the MQL5 language corresponds to the priority adopted in C++, and differs from the priority given in the MQL4 language.

[[Deleted]]

FinGeR:

I found a mistake 

If only one chart window is open. Then the ID of this window of  =  -1 

-

 

My mistake, it is true. :)

int WindowHandleMQL4(string symbol,
                     int tf)
  {
   ENUM_TIMEFRAMES timeframe=TFMigrate(tf);
   long currChart,prevChart=ChartFirst();
   int i=0,limit=100;
   while(i<limit)
     {
      
         currChart=ChartNext(prevChart);
      if(i==0)currChart=prevChart; // Wenn nur ein Chartfenster offen ist
  
      if( currChart<0) break;
        
      if(ChartSymbol(currChart)==symbol
        && ChartPeriod(currChart)==timeframe)
        
         return((int)currChart);
      prevChart=currChart;
      i++;
     }
   return(0);
  }

[nonor]

Hello

I will be pleased to know if all these functions have been validated, I didn't succed

to make the function "CopyBufferMQL4" working.

Thank you

Noel