MQL4: Execute function if x is more than y

Question

Using MQL4, how can I execute a BUY order (seen below)
if one variable x has a value of 1
and another variable y has a value of 3?

I need it to work like this:

Variable x = 1

Variable y = 3

So if x is MORE THAN y, execute this script:

extern int TakeProfit = 10;
extern int StopLoss = 10;

void OnStart()
  {
   double TakeProfitLevel;
   double StopLossLevel; 

   TakeProfitLevel = Bid + TakeProfit*Point;
   StopLossLevel = Bid - StopLoss*Point;

   Alert("TakeProfitLevel = ", TakeProfitLevel);
   Alert("StopLossLevel = ", StopLossLevel);

   OrderSend("USDCAD", OP_BUY, 1.0, Ask, 10, StopLossLevel, TakeProfitLevel, "first order");

 }

And if x is LESS THAN y, execute this SELL script:

extern int TakeProfit = 10;
extern int StopLoss = 10;

void OnStart()
{
double TakeProfitLevel;
double StopLossLevel; 

TakeProfitLevel = Bid + TakeProfit*Point;
StopLossLevel = Bid - StopLoss*Point;

Alert("TakeProfitLevel = ", TakeProfitLevel);
Alert("StopLossLevel = ", StopLossLevel);

OrderSend("USDCAD", OP_SELL, 1.0, Ask, 10, StopLossLevel, TakeProfitLevel, "first order");

}

I'm struggling to find the MQL4 code which establishes variables which can then be compared against each other e.g. x > y and vice versa, so any help would be greatly appreciated.

Answer 1

So, on the variables:

MQL4 used to be a compiled, static typed language.

So the source-code contains all prior declarations, so as to allow the compiler to assume, what the heck the variable has as it's type ( and internal representation ).

int             ii = 0;
double       coeff = 1.23456789;
color  anMQL_color = 0x224466;             // could be stated as {int|hex|literals||colornames}
datetime  aTimeNOW = D'2016.08.23';
string    aLastMSG = "[ALARM] This TracePoint shall never be executed";

Recent MQL4 language redesigns into a New-MQL4.56789 have brought both a few new types ( i.e. struct-s )

The basic data types are:

·integers (char, short, int, long, uchar, ushort, uint, ulong);

·logical (bool);

·literals (ushort);

·strings (string); ( but are struct internally (!!), so be carefull in DLL API )

·floating-point numbers (double, float);

·color (color);

·date and time (datetime);

·enumerations (enum).

Complex data types are:

·struct;

·class-es.

New language has also introduced a type casting, like this one:

int aFactoredNUMBER = EMPTY;                             // declaration + initial value assignment
    aFactoredNUMBER = (int) ( coeff * 3.1412592653598 ); // operation with a resulting value type casting into (int)

So how about the x > y ?

let me sketch a few SLOCs:

double x = 1,
       y = 3;
...
..
.

if (  x > y ) { ... ;
                OrderSend( , OP_BUY,  ... );
                return;
                }

if (  x < y ) { ... ;                            // THIS
                OrderSend( , OP_SELL, ... );     // COULD BE A CALL TO FUN( { OP_BUY | OP_SELL } )
                return;
                }