User Defined Functions / Forum: Forex Trading with MetaTrader 4

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User Defined Functions

dwt5dwt5 2005.09.27 22:44

I'm "still learning" how to program and wanted to create and use a User Defined Function, however I guess I don't understand how to do this. I am modifying an indicator which uses the following code mulitple times. I thought it best to create a function and call it rather than duplicate these lines of code 5 or 6 times..

RangeLimit = High[i];
for ( j = i - 7 ; j < i + 7 ; j++)
{
if (High[j] > RangeLimit)
{
RangeLimit = High[j];
}
}

I tired to create a function like this but keep getting "function definition unexpected"..

int FindRange( int x)
{
RangeLimit = High[x];
for ( j = x - 7 ; j < x + 7 ; j++)
{
if (High[j] > RangeLimit)
{
RangeLimit = High[j];
}
}
return(RangeLimit);
}

would someone mind teaching a newbie how to do this correctly...

thanks in advance

david

239

ShimodaxShimodax 2005.09.27 22:58

You probably put the function inside another or accidentally left out one of the curly brackets in the function above. However, I see a couple of things. The return value RangeLimit should be defined inside the function, not as a global variable. Also it should be a double, not an int.

Something like this:

int start()
{
   ....


   RangeLimit= FindRange(i);

   ...

}


double FindRange( int x)
{
   double rl;   // define variables used in a function inside that
   int j;    // function so they don't mix with the rest of the program

   rl= High[x];
   for ( j = x - 7 ; j < x + 7 ; j++)
   {
      if (High[j] > rl)
      {
         rl= High[j];
      }
   }

   return(rl);
}

Or alternately (I'm just showing off here, please bear with me, grin)

double FindRange(int x)
{
   double rl= 0;  // 0 won't be able to remain max value with prices
   for (int j = x - 7 ; j < x + 7 ; j++)
   {
      rl= MathMax(rl, High[x]);
   }
   return rl;
}

But the idea of a newbie putting repeated code into a function shows much promise ... with that mindset you'll soon become a proficient programmer!

Markus

dwt5dwt5 2005.09.27 23:30

Markus,

thanks for the input.. Great catch about returning double, I don't know why, but I was thinking I'd return the bar when I should have been returning the price...Silly me...

Anyway, I tried what you suggested, but I guess I'm still not gettting it as I got the same error message.. Would you mind if I sent you the indicator and let you modify it..

Thanks in advance..

d

239	ShimodaxShimodax 2005.09.27 23:44 David, just mail it to m.schmidt@emtec.com Markus

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