a problem about assignment for parameters

[Fa Cao]

A:

bool isFirst = true;
datetime  time_current;
int init(){
   if(isFirst) 
   { isFirst = false; 
    time_current=TimeCurrent();
    }

B:

extern bool isFirst = true;
extern datetime  time_current;
int init(){
   if(isFirst) 
   { isFirst = false; 
    time_current=TimeCurrent();
    }

Regarding codes 'A' and 'B', after they have been attached to a chart, the parameter, time_current, will never change when timeframe is changed (never be initiated again) in 'A', but do in 'B'; however we can set the parameter ,

time_current, when the code is attached to a chart in 'B', but we can't do like this in 'A'; (of course, the assignment when attached in this code is nonsense here, but i will in other place.)

So how to  set variables' value when EA is being attached like B and the variables can never been changed when shift time frame like in A?

[Ubzen]

I do-not understand why are you using this flag. Are you trying to stop something from happening when the program goes through a de-init and re-init cycle? Is this for an indicator... is this for an expert advisor? Please list the cases you're trying to avoid by using that variable.

[Ian Venner]

If you want persistant data write it to a file or set a global variable.

[Keith Watford]

Haven't you already covered this here?

https://www.mql5.com/en/forum/147862

[Fa Cao]

GumRai:

Haven't you already covered this here?

https://www.mql5.com/en/forum/147862

yes, i am

but this problem can't be resolve until now

so i list it here more clearly.

[Ubzen]

vx0532:

yes, i am

but this problem can't be resolve until now

so i list it here more clearly.

Perhaps you should re-read the advices already given?

[William Roeder]

vx0532: So how to set variables' value when EA is being attached like B and the variables can never been changed when shift time frame like in A?

When in doubt, THINK.

bool isFirst = true;           // Can't be changed by human.
extern datetime  initial_time; // Can be changed whenever, but used on first load only.
datetime  time_current;        // Can't be changed = initial_time on first load.
int init(){
   if(isFirst) 
   { isFirst = false; 
     time_current=initial_time
   }

Don't double post.