The original code uses standard C/C++ and is compiled into the Zorro executable. In standard C/C++, it is legal to declare an int in a for loop initialization, but not in Lite-C.

Hello,

Thank you so much for your earliest reply.

Just out of curiosity, in the manual (https://zorro-project.com/manual/en/tutorial_var.htm), it mentions that we can switch from Lite-C to C++.

Quote:

"Zorro gives you the choice to develop strategy scripts either in lite-C, a 'lightweight' version of the C programming language, or in 'full grown' C++"

Do you know how to switch?

Yes, instructions are here:
https://zorro-project.com/manual/en/dlls.htm

Hello,

I am trying to run the code below in order to better understand assigning index to a currency name:

function main()
{
#define MAXCURRENCIES 32
var CStren[MAXCURRENCIES],CStrenSum[MAXCURRENCIES];
int CNum[MAXCURRENCIES];
char CNames[128];
int NumCurrencies = 0;

int ccyIdx(char* name)
{
char Ccy[4];
memcpy(Ccy,name,4);
Ccy[3] = 0;

for(int n=0; n<MAXCURRENCIES; n++)
{
if(!CNames[n*4])
{ // not yet stored
strcpy(CNames+n*4,Ccy);
NumCurrencies++;
return n;
}
if(strstr(CNames+n*4,Ccy))
return n;
}

return 0;
}

}

I am receiving the following error:

Error in 'line 14:
'name' undeclared identifier
memcpy(Ccy,name,4);

I kindly ask for some clarification

Step 1 is to learn the C language. You cannot declare functions inside another function.

Hello,

Understood. I am trying to better understand C through learning the indicators source codes and applying them in my scripts. I grabbed a little of tips as I progress.

Regarding the assigning an index to a currency name. I can almost see the loop and the logic, yet it remains slightly unclear.

Code:


I do not understand the !CNames[n*4] part.
The ! stands for not. I cannot see or understand the logic. How do we know if it is stored or not.

The way I am reading it at first is, if (CNames[0] is not, then copy the string from Ccy to CNames with a 0 etc)
But what is the logic and where is it written.
If the first element in the CName array is not what exactly?

Thank you so much for the help

It’s checking for null terminators at the beginning of each string.

Think of this value in memory (0 is literal zero not the character for 0)

CNames = "EUR0USD0GBP00000"

n = 3
i = 3*4 = 12

CNames[12] == 0 <- true
!CNames[12] is !0 which is true as well

Greetings,

I would like to thank everyone who has replied to me (especially AndrewAMD).

I just wanted to ask a small question. In the earlier post it was mentioned that you cannot declare a function inside a function. I am assuming this referred to int ccyIdx(char* name) inside function main(). So how do we run the function ccyIdx(char* name) without function main()?

Declare and define the functions outside of main and prior to main. Inside main, invoke the functions you defined.