Array Problem

[Jason]

When I do the following:
Add an array and a counter to the frame.

In the events menu add the following events and actions:
Start of Frame - Set x index of array to 1
When pressing Space (keyboard) - Add 1 to x index of array
Always - Set counter to x index of array

When I run the program it starts with the counter equal to 10 (it should start with the counter equal to 1) and no matter how many times I press the space key the counter does not change. I did make sure the type of array was "number."

Am I missing something?

Jason

[Skyhunter]

It works normally for me. You should probably check your code.

[Pixelthief]

The "index" property of an array is simply a pointer to where in the array it will retrieve data from using the "get value at current position" function. The index is not part of the array storage itself, and is limited by the size of any array- a size 10 array cannot have an index point beyond 10 (because logically this would cause an out-of-bounds error)


I believe you are trying to use the array object in the wrong way. If you want to store data in it, you'll want to use the functions:


"Write Value to X"
and
"Read Value from X"


an example of a 1x1x1 array that stores just a single variable like a counter would run like this:



Start of Frame - Write Value (1) to (X = 1)
When pressing Space - Write Value ((Read Value at (X = 1)) + 1) to (X = 1)
Always - Set counter to (Read Value at (X = 1))



Think of an Array as a line (1 dimensional), square (2 dimensional) or cube (3 dimensional). Lets use a square for an example. Lets say we have a 10x10x1 array- this is the same as a 10x10 square. Each tile on that 10x10 square can hold a variable, for 100 tiles total. There can be 100 different numbers written into it, 1 in each slot.

The index is simply a value for 1 to 10 for X, and 1 to 10 for Y, that points to one of these tiles when combined. So at index X=5, Y=5, you might retrieve whatever value was written there.


In general you don't need to use the indexes at all- just directly retrieve and write variables from the positions in the expression editor. Using the indexes is just there to make some things easier to write, like if you were trying to access the same position over and over- you could set the indexes, then just read/write from the currently active index.

For example:


Start of Frame - Set X index of array to (1)
Start of Frame - Write value to current position (1)

When Pressing Space - Write value to current position ((Read Value from current position) + 1)

Always - Set counter to (Read value from current position)

[Chaos]

I have an array example on my website also that covers this if you need a visual aid.

[Jason]

I see what I was doing wrong. Instead of setting the counter to the current x index I was setting the counter to the x dimension (the size of the array).

Jason