How to update variable from with if statement MQL5

[AnwarGoulouh.001]

https://stackoverflow.com/questions/58228952/how-to-update-variable-from-with-if-statement-mql5

[AnwarGoulouh.001]

PLease check stack overflow couldn't seem to add the short code here kept saying it was exceeding char limit. :(

[Pavel Shutovskiy]

you need to set a NULL pointer to a variable int a = NULL;

   int a = NULL;
   if(PositionsTotal() < 1)
     {
      if(a == NULL || a == 1)
        {
         a = 0;
        }
      else
         if(a == 0)
           {
            a = 1;
           }
     }
   Print(a);

I will add my opinion: it is better to use the standard 0 because NULL is a compiler macro, and it can have a value other than 0

[William Roeder]

Pavel Shutovskiy: I will add my opinion: it is better to use the standard 0 because NULL is a compiler macro, and it can have a value other than 0

I agree.

Don't use NULL.

• You can use NULL in place of _Symbol only in those calls that the documentation specially says you can. iHigh does, iCustom does, MarketInfo does not. OrderSend does not.
• Don't use NULL (except for pointers where you explicitly check for it.) Use _Symbol and _Period, that is minimalist as possible and more efficient.
• Zero is the same as PERIOD_CURRENT which means _Period. Don't hard code numbers.
• MT4: No need for a function call with iHigh(NULL,0,s) just use the predefined arrays, i.e. High[].