Help with Arrays
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I've read through 28 days 2 paragraph snippet on arrays and a few forum posts but I still don't fully understand them.
So from what I understand, to create an array just do something like this

Code:

; Totaly random unused of data im using for an example
Array:
   .db   7,0,0,0,0,0,0,0,0,9,0,0,0
   .db   0,0,0,0,0,2,0,0,0,0,0,3,0
   .db   0,0,0,0,0,2,6,0,0,0,0,0,6
   .db   2,0,4,0,0,0,0,0,0,8,0,0,0
   .db   4,0,0,0,1,1,2,8,0,0,0,0,0

But im not 100% on how to access this array. What I'm trying to do is store a map in an array, and then read through the array, printing some predertimined char for each number in the array (0=' ', 1='+', simple stuff).
But I have no clue how to access the array, I assume its something like

Code:

LD HL,(Array)+2

or something, but if someone could clear this up It'd be appreciated Good Idea
In fact it's just a large list. Since you are using 1-byte values, you need register A and not HL, and you can access elements with
Code:
ld a, (Array + N)
where N is the element index. Hope this helps Smile
Sola Fide
There's two ways to access this. First is to create a pointer to the Array. Second is use the Array label (which is a pointer itself).

Pointer to Array in HL

Code:
ld hl, Array
ld bc, [Offset in Data]
add hl, bc
ld a, (hl) // your byte is in a


Use Array Itself

Code:
ld a, (Array + Offset)



Sometimes, you need to use the first example. For instance, if you need to iterate through the data or a segment of it within a loop, you will need the first example, because in the ld a, (Array + Offset) example, Offset must be defined at compile time and cannot be a variable.


Edit:
In your example: ld hl, (Array)+2, that would load into HL, the value at Array, and then add 2 to it.
So are these two arrays equivalent?

Code:

Array1:
 .dw 0,1,2,3,4,5,6,7,8,9

Array2:
 .dw 0,1,2,3,4
 .dw 5,6,7,8,9


Are elements in 2D arrays just stored one after another in memory?If so would this run and exit correctly or would this do what the comment says?

Code:

LD A,(Array1 + 6)
LD B,A
LD A,(Array2 + 6)
CP B
RET z
; If not zero read through fancy important calculator code and crash everything


Edit:
Also, I'm having an issue where elements in my array aren't correct, Let's say I have this;

Code:

LD A,(Map + N)
BCALL(_PutMap)

Map:
   .dw $20,$21,$22,$23,$24,$25,$26,$27,$28


So Would the first element in the array be N=0 or N=1?
Also, can I do what the code above is doing? or is my problem that When N=0 in loading $2 into A and when N=1 in loading $0 into A?
You are using .dw when you should be using .db
.dw is 'define word' - regarding z80 this is a 16-bit, or 2 byte word. If you want to get any specific word it would be (Map + (N * 2)) since each element in your array would be 2 bytes if defined this way.

.db is 'define byte' - as Mateo suggests, would suit (Map + N). And you would indeed stat at N=0, since this would leave you with just 'Map', which is the location of your array.
"My world is Black & White. But if I blink fast enough, I see it in Grayscale."

  
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