Declaring a simple Array ( Length )

[pstrusi]

Hi Ninjas,

I want to declare a simple array length, through the standard syntax:

double[] myfirstarray = new double[10];

This declaration goes under Variable region, but here the question:

How can I declare that array length with an integer number not just changing the code internally, but rather when I run it, let's say running the Strategy Analyzer for a backtest. When I try to declare this array with a previous integer variable above, I always get the obvious error.

What I'd like is declaring the array length from outside of the code.

Thanks for your help

[NinjaTrader_ChelseaB]

Hi pstrusi,

If you are wanting to start with a new array you can change the size at that time.

In #region Variables
double[] myfirstarray = new double[10];
int arraySizeVariable = 20;

In OnBarUpdate() or OnStartUp() (or wherever you want to set the array size)
if (/* conditions to set array size */)
myfirstarray = new double[arraySizeVariable];


Or you can use a list that is dynamically expanding.

[pstrusi]

Thank you so much Chelsea, I didn't think the possibility of OnStarUp()


Have a nice weekend and best regards

[pstrusi]

Chelsea, I've been trying your suggestion but is not allowed to change the initial declaration of the array, this is the error message:

Error on calling 'OnBarUpdate' method for strategy 'FFFS/c8e4482eaaaa49238463f1e35b50f195': Index was outside the bounds of the array.


When I let just the initial declaration, all runs ok

[NinjaTrader_ChelseaB]

Hi pstrusi,

Your error will be due to some other logic in your code.

Attached is an example to demonstrate that this works.

[pstrusi]

Thanks for the example, despite the same you told before it's very helpful. I've found the problem, yes it was in the logic, apparently I had to add 2 to the variable "myarrayinteger" , a little part in the logic requires this, I had overlooked it.

Thanks again