variablesmql4

In MQL4 the variable doesn't change

I am starting to learn MQL4 and wanted to write a simple program for practice. When I open a long position, the positions variable is supposed to take the value 1, and when I take a short position, the positions variable is supposed to take the value -1. Unfortunately, after the loop is executed, the variable is still 0. What am I doing wrong? PS. Close_Trade is my internal function and works well.

void OnTick()
  {
   
     {
      double stoch= iStochastic(NULL,0,14,3,3,0,1,0,0);
      int number_of_order= OrdersTotal();
      static int positions=0;
      if(number_of_order==0)
        {
         if(stoch<=20)
           {
            int purchase_order=OrderSend(_Symbol,OP_BUY,0.01,Ask,0,0,0,NULL,0,0,clrNONE);
            positions++;
           }
         else
            if(stoch>=80)
              {
               int sales_order=OrderSend(_Symbol,OP_SELL,0.01,Bid,0,0,0,NULL,0,0,clrNONE);
               positions--;
              }
        }
       Alert(positions);
     if(stoch>70 && positions==1)
        {
         Close_Trade();
         positions--;
        }
      if(stoch<30&&positions==-1)
        {
         Close_Trade();
         positions++;
        }
     }

  }
//+------------------------------------------------------------------+

I added a static to the position variable, but that didn't help.

Solution

  • Short answer: delete static int positions=0; from OnTick function and write out and before OnTick function. No need to write static.

    Long answer:

    Please put the line numbers in the next questions

    However, the problem is in the line

        static int positions=0;

    Behold

    The process of your program is that your code is executed once for each market tick

    1. In double stoch= iStochastic(NULL,0,14,3,3,0,1,0,0); the value of the stoch variable is set, for example, we assume its value is equal to 15.
    2. In int number_of_order= OrdersTotal();, number_of_order takes a value equal to OrdersTotal(), we assume that you do not have an open order and the value of this variable is equal to 0.
    3. In static int positions=0; the position variable takes the value 0.
    4. Since you don't have an open order, the program enters the if(number_of_order==0).
    5. Because the stock value is below 20, so program enters if(stoch<=20) and opens an order, and position increases by one unit and becomes equal to 1.
    6. In Alert(positions); it gives a warning and outputs the value of the position, which is 1 (it is useless to warn the value of the position variable in every market tick, write the program in such a way that it alert if the value of the position changes. I think this is better).
    7. Because the value of the stoch is 15 and the value of the position is 1, the program does not enter the remaining two if statements and the value of the position is still equal to 1.

    The program ends and waits for the next market tick (which is very short). At the beginning of the next tick, the stoch variable is reset with ouble stoch= iStochastic(NULL,0,14,3,3,0,1,0,0);. In int number_of_order= OrdersTotal();, number_of_order becomes 1. The value of the position, which is equal to 1, will be equal to 0 with static int positions=0;.

    This is the problem with your program You have to delete static int positions=0; from OnTick function and write out and before it. No need to write static.