; array stuff - Friday, February 25, 2011 - 3:01:44 AM
include \masm32\include\masm32rt.inc
intw typedef sword ;typedef examples
char typedef byte
;initialized variables
.data
pi db 3.14
myString db "this is my string",0
x real4 1.5
y real8 1.0e-25
z real10 -1.2594e+10
myInt intw 2
squares char 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
ary DWORD 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 \
,21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40
;uninitialized variables
.data?
bytevar db ?
wordvar dw ?
dwordvar dd ?
quadword dq ?
firstword dd ?
secondword dd ?
arr2 dd 40 dup (?)
.code
start:
mov ebx, 0 ; start at 0
.while ebx < sizeof ary ; loop until we reach sizeof ary
add ebx, 2 ; count up by 2
mov eax, [ary+ebx] ; store item to eax
mov secondword, eax ; store eax in secondword
print addr secondword, 13, 10 ; print secondword - carriage / line feed
.endw
inkey "press any key to quit"
exit
end start
This works but it prints the symbol instead of the number I want... how do I print the actual contents in this case? 1, 2, 3 of ary ?
uses the udword$() macro for converting the dword to an string. Also take care of operand sizes.
Hi j00n,
A qucik example for you :
include PrintArray.inc
NUMB_OF_ELEMENTS = 10
.data
array dd 1,2,3,4,5,6,7,8,9,10
format1 db '%d',13,10,0
.code
start:
call PrintArray
invoke ExitProcess,0
PrintArray PROC USES ebx esi
LOCAL buffer[8]:BYTE
mov esi,OFFSET array
mov ebx,NUMB_OF_ELEMENTS
@@:
invoke wsprintf,ADDR buffer,ADDR format1,DWORD PTR [esi]
invoke StdOut,ADDR buffer
add esi,SIZEOF DWORD ; =4 , each element has a size of four bytes
dec ebx
jnz @b
ret
PrintArray ENDP
END start
hey thanks for the help I added some comments to see if you would clarify for me...
include PrintArray.inc
NUMB_OF_ELEMENTS = 10 ; is this a constant? I haven't seen this used before
.data
array dd 1,2,3,4,5,6,7,8,9,10
format1 db '%d',13,10,0
.code
start:
call PrintArray
invoke ExitProcess,0
PrintArray PROC USES ebx esi ; uses - doesn't this preserve the registers?
LOCAL buffer[8]:BYTE
mov esi,OFFSET array ; I forgot the difference of offset / addr, why offset in this case?
mov ebx,NUMB_OF_ELEMENTS
@@:
invoke wsprintf,ADDR buffer,ADDR format1,DWORD PTR [esi] ; could you explain the last bit for me?
invoke StdOut,ADDR buffer
add esi,SIZEOF DWORD ; =4 , each element has a size of four bytes
dec ebx
jnz @b ; jump back
ret
PrintArray ENDP
END start
Hi j00n,
NUMB_OF_ELEMENTS is a constant to make more readable the source code.
mov ebx,NUMB_OF_ELEMENTS is more easy to understand compared to
mov ebx,10USES ebx esi will preserve only ebx and esi. Have a look at here (http://www.masm32.com/board/index.php?topic=4205.0) for more details.
About ADDR :
QuoteThe addr operator is used to pass the address of a label to the function. It's valid only in the context of invoke directive. You can't use it to assign the address of a label to a register/variable, for example. You can use offset instead of addr in the above example. However, there are some differences between the two:
addr cannot handle forward reference while offset can.
Have a look at Iczelion's tutorial MessageBox (http://win32assembly.online.fr/tut2.html) for an example.
About wsprintf , from win32.hlp :
QuoteThe wsprintf function formats and stores a series of characters and values in a buffer. Any arguments are converted and copied to the output buffer according to the corresponding format specification in the format string. The function appends a terminating null character to the characters it writes, but the return value does not include the terminating null character in its character count.
The purpose is to print a number followed by a CR+LF pair, ASCII 13+10
wsprintf will replace %d with each elements of the array. %d is user for signed decimal integer arguments. esi points the number array and DWORD PTR [esi] holds the value of each element. Suppose that esi = 402000h :
402000h -> 1
402004h -> 2
402008h -> 3
.
.