That's the spirit :)
If you know arrays in java or js, let me explain it like this in C2.
Arrays have fixed, given dimensions in C2. You can't just "push" a new element inside, you set a value at a given index X in your array (well, you can push, but it won't change the array size).
C2 gives you the option for multi dimensional arrays though, up to 3 dimensions. That means that you can have 3 index, X Y and Z.
In your case, I would use only 2 dimensions.
X would be the obstacle number (0 for the first arrow, 1 for the second arrow, ...)
For a given X, we would store at Y=0 the timestamp and at Y=1 the arrows.
Think of a matrix, with the first column being the timestamp, second one the arrows, a line for each arrow sequence.
You access a data in an array using the "Array.At(X,Y)" instruction.
Take a look to the manual on this subject for more infos.
Last thing, you don't need to store an array to store 2 or more arrows. Just use a single string.
"T" => top
"L" => left
"B" => bottom
"R" => right
"TLB" => Top + left + bottom.
How to analyse this string in C2 ?
just do 4 test for each string :
if (tokencount(mySting,"T")>0) => there is a top arrow
if (tokencount(mySting,"B")>0) => there is a bottom arrow