How to retain local value of variable?

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selnomeria
231
selnomeria  

I know, that in some cases non-buffered variables are lost. for example


static int MyVariable =0;

......

MyVariable =  (Condition ?   MyVariable+1  : MyVariable );

......


but in some cases i found (when something changed on chart or input or etc.. without refreshing the chart F5 ), the value of that variable is nulled.

I was advised to use buffers for such variables:


MyVariable[i] =  (Condition ?   MyVariable[i+1] +1  : MyVariable[i+1] );


however i have tens of such repeated variables in my indicators/scripts, and i cant set buffers for those variables... is any other solution? for example, what if i use array, will it be nulled too?

static int MyAr[1];

....

MyAr[0]= (Condition ? MyAr[0]+1 : MyAr[0]);

....



any help?

selnomeria
231
selnomeria  

any help?

Drazen Penic
2955
Drazen Penic  

If your variable unexpectedly gets lost or nulled, then you have a bug in your code.

William Roeder
19846
William Roeder  
  1. Definitely a bug in your code.
    however i have tens of such repeated variables in my indicators/scripts, and i cant set buffers for those variables
    Of course you can. But if you don't, you need their previous value(s) to do the current bar which is a problem with bar zero. Either buffers, only process bar zero once, or save and restore them when processing bar zero.
  2. static int MyAr[1];
    Why would define an array that only has one value?
  3. MyAr[0]= (Condition ? MyAr[0]+1 : MyAr[0]);
    
    Why would you write such code? if(condition) ++MyArray[0]; is simpler and 3 times faster.
selnomeria
231
selnomeria  
whroeder1:

thanks, i have a question, what means process bar zero only once? can you give me example, i dont understand what subject  (about zeros..) you are talking about....

In my indicator, if i left it in live chart, and clicked refresh, then many values of such "one-time" variable values were lost, and that's why i dont know what happened...  If i re-attached indi to chart, then values were correct.

William Roeder
19846
William Roeder  
  1. "Only once?" I gave you the link. Either only use opening values
       const int   lookback    = ...;
       int      iBar  = Rates_total - MathMax(lookback, prev_calculated);
       while(iBar > 0){  --iBar;
          // calculate buffer[iBar]
       }
       #define  REDRAW_BAR_LAST false      // Don't redraw Bar zero.
       return   rates_total - REDRAW_BAR_LAST - iBar;
    or never update bar zero
       const int   lookback    = ...;
       int      iBar  = Rates_total - MathMax(lookback, prev_calculated);
       while(iBar > 1){  --iBar;
          // calculate buffer[iBar]
       }
       #define  REDRAW_BAR_LAST false      // Don't draw Bar zero.
       return   rates_total - REDRAW_BAR_LAST - iBar;

  2. Variables are not lost. If prev_calculated is zero, you must initialize them, you are not. Your code is broken, fix your broken code.
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