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Index > DOS > (newbe) Problem printing array value

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umen



Joined: 14 Aug 2005
Posts: 16
umen
Hello all
im trying to print the array value put with out success, it always prints me the first array member value
here is the code :

Code:
-----------------------------------------------------------
DSEG SEGMENT
THEARRAY DB '1000$','2000$','3000$','4000$','5000$'                                         
DSEG ENDS
SSEG SEGMENT STACK                             
DW  100H DUP(0)
SSEG ENDS
CSEG SEGMENT
ASSUME DS:DSEG,SS:SSEG,CS:CSEG
START:
MOV DI,0
 MOV DX,OFFSET THEARRAY[0]
   MOV AH,9
   INT 21H
   INC DI
 MOV DX,OFFSET THEARRAY[4]
   MOV AH,9
   INT 21H
   INC DI
 MOV DX,OFFSET THEARRAY[9]
   MOV AH,9
        INT 21H
 MOV DX,OFFSET THEARRAY[14]
   MOV AH,9
        INT 21H
    MOV AX,4C00H
    INT 21H
CSEG ENDS
END START
    
Post 14 Aug 2005, 19:12
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gunblade



Joined: 19 Feb 2004
Posts: 209
gunblade
arrays dont work that way in asm.. thats C your thinking of.

what you do is.. say you have an array of single bytes
Code:
array db 21, 40, 31    

if you want the address of the first element, do
Code:
mov dx, array    

for the address of the second element, you take the base address (array) and add the number of elements you want to skip.. so:
Code:
mov dx, array+1    
for the address of the second element.
If this array was an array of words though (2bytes each, then to access the address of element 2, you would do:
Code:
mov dx, array+2    
)

I hope that was kinda clear. Feel free to ask otherwise.
Post 15 Aug 2005, 20:09
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umen



Joined: 14 Aug 2005
Posts: 16
umen
Ok first tnx for the reply .. this is confusing me a lot this simple array manipulation just don’t work in any way I try to print the element
Please.. please some one take this code and try to run it .. it is just don’t work. let me understand why...
Code:
------------------------------------------------------------------------
DSEG SEGMENT
THEARRAY DB 23,56,88,99                                  
DSEG ENDS
SSEG SEGMENT STACK                             
DW  100H DUP(0)
SSEG ENDS
CSEG SEGMENT
ASSUME DS:DSEG,SS:SSEG,CS:CSEG
START:
 MOV DX,THEARRAY
   MOV AH,9
   INT 21H
 MOV DX,THEARRAY+1
   MOV AH,9
   INT 21H
 MOV DX,THEARRAY+2
   MOV AH,9
   INT 21H
 MOV DX,THEARRAY+3
   MOV AH,9
        INT 21H
    MOV AX,4C00H
    INT 21H
CSEG ENDS
END START
------------------------------------------------------------------------
this one gives me this error: 
tst1.asm(10) : error A2070: invalid instruction operands
tst1.asm(13) : error A2070: invalid instruction operands
tst1.asm(16) : error A2070: invalid instruction operands
tst1.asm(19) : error A2070: invalid instruction operands
-----------------------------------------------------------------------
when i try this code : 

DSEG SEGMENT
THEARRAY DB 23,56,88,99                                        
DSEG ENDS
SSEG SEGMENT STACK                             
DW  100H DUP(0)
SSEG ENDS
CSEG SEGMENT
ASSUME DS:DSEG,SS:SSEG,CS:CSEG
START:
 MOV DX,OFFSET THEARRAY
   MOV AH,9
   INT 21H
 MOV DX,OFFSET THEARRAY+1
   MOV AH,9
   INT 21H
 MOV DX,OFFSET THEARRAY+2
   MOV AH,9
   INT 21H
 MOV DX,OFFSET THEARRAY+3
   MOV AH,9
   INT 21H
    MOV AX,4C00H
    INT 21H
CSEG ENDS
END START
-----------------------------------------------------------------------
    

the result is bench of crap on the screen ….


what is wrong here ? please help
thenks allot
Post 16 Aug 2005, 13:19
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Matrix



Joined: 04 Sep 2004
Posts: 1171
Location: Overflow
Matrix
hi umen,
you have to make your own functions to use your arrays,

my example

Code:
org $100

push ds ; in case of exe file
push cs
pop ds

mov si,THEARRAY
mov bx,0
call printelement

mov si,THEARRAY
mov bx,1
call printelement

mov si,THEARRAY
mov bx,2
call printelement

mov si,THEARRAY
mov bx,3
call printelement

mov si,THEARRAY
mov bx,4
call printelement

mov si,THEARRAY
mov bx,5
call printelement

;waitkey;
xor ah,ah
int 16h

pop ds

MOV AX,4C00H
INT 21H

THEARRAY: db "Array element1*","$","Array Element2*","$","Array Element3*","$","Bonus element*","$",0
;THEARRAY: db "Array element1$","Array Element2$","Array Element3$","Bonus element$",0
;THEARRAY: db "helloszia$","sziaszia$","imallright$",0

printelement: ; proc print array element, in a null terminated array
              ; (ds:)si = parameter input, bx=element to print, 0 is first
or bx,bx
jz .write
.loop:
lodsb
or al,al ; out of range?
jz .error
cmp al,"$"
jne .loop
dec bx
jmp printelement
.error: ; display error message
mov dx,.ermsg
mov ah,9
int 21h
jmp .done
.write:
lodsb
or al,al
jz .error
dec si
mov dx,si
mov ah,9
int 21h
.done:
ret
.ermsg: db "out of range.*","$"
    
Post 16 Aug 2005, 13:59
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