Compile error mt4 expression not boolean ?

[geoff hornibrook]

Can anyone help me ?

when I compile in mt4 strategy tester it says expression not boolean ? it used to say something like 0 errors 0 faults etc ?

It's got me, it still compiles the expert advisor ok but Its not confirming that there is no errors in the programme.

Geoff

[Piptide]

Assuming you mean MetaEditor, not Strategy Tester, but you probably used a single equal sign in a place where you need two.  Use a single = when assigning values and == when evaluating something in an expression. For example:

if(OrderType()==0  <--Compiler is happy

if(OrderType()=0 <-- Expression is not boolean error

If you post the line of code it's complaining about I'm sure we can find it quickly.

[MATTHEW STAN WILLS]

Piptide:

Assuming you mean MetaEditor, not Strategy Tester, but you probably used a single equal sign in a place where you need two.  Use a single = when assigning values and == when evaluating something in an expression. For example:

if(OrderType()==0  <--Compiler is happy

if(OrderType()=0 <-- Expression is not boolean error

If you post the line of code it's complaining about I'm sure we can find it quickly.

Have the same problem,

here is my code:

//--- Has the candle actually formed
bool ValidCandleCheck(string symbol, ENUM_TIMEFRAMES timeframe)
{
   double low = iLow(symbol,timeframe,0);
   double high = iHigh(symbol,timeframe,0);   
   if( MathAbs( high - low ) == 0 || low == 0 || high == 0 )
   {
      return(False);
   }
   else
   {
      return(True);
   }
}

[Konstantin Nikitin]

//--- Has the candle actually formed
bool ValidCandleCheck(string symbol, ENUM_TIMEFRAMES timeframe)
{
   double low = iLow(symbol,timeframe,0);
   double high = iHigh(symbol,timeframe,0);   
   if( MathAbs( high - low ) == 0 || low == 0 || high == 0 )
   {
      return(False);
   }
   else
   {
      return(True);
   }
   return(True);
}

or

//--- Has the candle actually formed
bool ValidCandleCheck(string symbol, ENUM_TIMEFRAMES timeframe)
{
   double low = iLow(symbol,timeframe,0);
   double high = iHigh(symbol,timeframe,0);   
   if( MathAbs( high - low ) == 0 || low == 0 || high == 0 )
   {
      return(False);
   }
   return(True);
}

or

//--- Has the candle actually formed
bool ValidCandleCheck(string symbol, ENUM_TIMEFRAMES timeframe)
{
   double low = iLow(symbol,timeframe,0);
   double high = iHigh(symbol,timeframe,0);   
   
   return(( MathAbs( high - low ) == 0 || low == 0 || high == 0 ) ? False : True);
}

[William Roeder]

//--- Has the candle actually formed
bool ValidCandleCheck(string symbol, ENUM_TIMEFRAMES timeframe)
{
   double low = iLow(symbol,timeframe,0);
   double high = iHigh(symbol,timeframe,0);   
   
   return !( MathAbs( high - low ) == 0 || low == 0 || high == 0 );
}

or

//--- Has the candle actually formed
bool ValidCandleCheck(string symbol, ENUM_TIMEFRAMES timeframe)
{
   double low = iLow(symbol,timeframe,0);
   double high = iHigh(symbol,timeframe,0);   
   
   return MathAbs( high - low ) != 0 && low != 0 && high != 0;
}

[Alexis Tormo]

whroeder1:
or

Hi, something like this happens to me, with the new version I get a warning of "not boolean expression" in this code. Can you tell me what the right code is?

f ((UseFridayFinalTradeTime && (Hour()>=FridayFinalHourGMT + ServerTimeZone) && DayOfWeek()==5)||DayOfWeek()==0)return (False); // Friday Control

[Keith Watford]

You used to be able to use True and False with the capitalized initial letter

now you must use

true and false - all lower case.

[Pantelis Papaisidorou]

Same problem here... Only it is not supposed to be a boolean... It's just an int (that i converted to double to dodge another unresponding-for no reason error).

Keith Watford:

You used to be able to use True and False with the capitalized initial letter

now you must use

true and false - all lower case.

[Keith Watford]

Pantelis Papaisidorou:

Same problem here... Only it is not supposed to be a boolean... It's just an int (that i converted to double to dodge another unresponding-for no reason error).

Show your code if you want help.

[Keith Watford]

Keith Watford:

You used to be able to use True and False with the capitalized initial letter

now you must use

true and false - all lower case.

This has changed since, you can use True and False again.

[Billionist]

SAME PROBLEM HERE WITH THIS CODE

//+------------------------------------------------------------------+
//|                                      KG Support & Resistance.mq4 |
//|                      Copyright © 2007, MetaQuotes Software Corp. |
//|                                        http://www.metaquotes.net |
//+------------------------------------------------------------------+
#property copyright "Kang_Gun"
#property link      "http://www.free-knowledge.com"

#property indicator_chart_window
#property indicator_buffers 8
#property indicator_color1 Yellow
#property indicator_color2 Yellow
#property indicator_color3 LimeGreen
#property indicator_color4 LimeGreen
#property indicator_color5 Blue
#property indicator_color6 Blue
#property indicator_color7 Red
#property indicator_color8 Red
//---- input parameters

//---- buffers
double ExtMapBuffer1[];
double ExtMapBuffer2[];
double ExtMapBuffer3[];
double ExtMapBuffer4[];
double ExtMapBuffer5[];
double ExtMapBuffer6[];
double ExtMapBuffer7[];
double ExtMapBuffer8[];
int KG;
//+------------------------------------------------------------------+
//| Custom indicator initialization function                         |
//+------------------------------------------------------------------+
int init()
  {
//---- indicators
   SetIndexStyle(0,DRAW_ARROW,STYLE_DOT,1,Yellow);
   SetIndexDrawBegin(0,KG-1);
   SetIndexBuffer(0,ExtMapBuffer1);
   SetIndexLabel(0,"Resistance M15");
   SetIndexArrow(0, 158);
   SetIndexStyle(1,DRAW_ARROW,STYLE_DOT,1,Yellow);
   SetIndexDrawBegin(1,KG-1);
   SetIndexBuffer(1,ExtMapBuffer2);
   SetIndexLabel(1,"Support M15");
   SetIndexArrow(1, 158);
   SetIndexStyle(2,DRAW_ARROW,STYLE_DOT,1,LimeGreen);
   SetIndexDrawBegin(2,KG-1);
   SetIndexBuffer(2,ExtMapBuffer3);
   SetIndexLabel(2,"Resistance H1");
   SetIndexArrow(2, 158);
   SetIndexStyle(3,DRAW_ARROW,STYLE_DOT,1,LimeGreen);
   SetIndexDrawBegin(3,KG-1);
   SetIndexBuffer(3,ExtMapBuffer4);
   SetIndexLabel(3,"Support H1");
   SetIndexArrow(3, 158);
   SetIndexStyle(4,DRAW_ARROW,STYLE_DOT,1,Blue);
   SetIndexDrawBegin(4,KG-1);
   SetIndexBuffer(4,ExtMapBuffer5);
   SetIndexLabel(4,"Resistance H4");
   SetIndexArrow(4, 158);
   SetIndexStyle(5,DRAW_ARROW,STYLE_DOT,1,Blue);
   SetIndexDrawBegin(5,KG-1);
   SetIndexBuffer(5,ExtMapBuffer6);
   SetIndexLabel(5,"Support H4");
   SetIndexArrow(5, 158);
   SetIndexStyle(6,DRAW_ARROW,STYLE_DOT,1,Red);
   SetIndexDrawBegin(6,KG-1);
   SetIndexBuffer(6,ExtMapBuffer7);
   SetIndexLabel(6,"Resistance D1");
   SetIndexArrow(6, 158);
   SetIndexStyle(7,DRAW_ARROW,STYLE_DOT,1,Red);
   SetIndexDrawBegin(7,KG-1);
   SetIndexBuffer(7,ExtMapBuffer8);
   SetIndexLabel(7,"Support D1");
   SetIndexArrow(7, 158);
//----
   return(0);
  }
//+------------------------------------------------------------------+
//| Custor indicator deinitialization function                       |
//+------------------------------------------------------------------+
int deinit()
  {
   return(0);
  }
//------------------------------------------------------------------  
bool Fractal (string M,int P, int shift)
  {
   if (Period()>P) return(-1);
   P=P/Period()*2+MathCeil(P/Period()/2);
   if (shift<P)return(-1);
   if (shift>Bars-P)return(-1); 
   for (int i=1;i<=P;i++)
     {
      if (M=="U")
        {
         if (High[shift+i]>High[shift])return(-1);
         if (High[shift-i]>=High[shift])return(-1);     
        }
      if (M=="L")
        {
         if (Low[shift+i]<Low[shift])return(-1);
         if (Low[shift-i]<=Low[shift])return(-1);
        }        
     }
   return(1);