Inserting values into array in assembly MASM32 - arrays

Question

I'm having trouble figuring out how to put a value I currently have in register EAX into an array.
The basic function of this program is to take the dates array, convert them to unique numbers, BubbleSort them, and convert them back.
I put the values I find with "datetonum" into EAX, and I want to store those values I find into my array named ra.
I can't seem to figure out how to do something that.
Seems like it should be fairly simple?
Thanks in advance!
include \masm32\include\masm32rt.inc
.data
dates BYTE "23-JUL-2010", 0, "23-JAN-2010", 0, "23-JUL-2009", 0, "31-JUL-2012", 0, "05-MAR-2010", 0
months BYTE "JAN",0,"FEB",0,"MAR",0,"APR",0,"MAY",0,"JUN",0,"JUL",0,"AUG",0,"SEP",0,"OCT",0,"NOV",0,"DEC",0
nDates DWORD 4
ra DWORD 1,0,0,0,0
.code
start:
lea EAX, dates ; create pointer to beginning of dates array
push EAX
call datetonum
;-------------------
;put value currently in EAX into array to be sorted
;-------------------
print "Array to be sorted contents: "
print chr$(13,10)
lea ECX, ra
mov [ECX + nDates], EAX
print ra
print chr$(13,10)
Here's the datetonum function
;param1 (date string) = address of 12 byte date
datetonum:
enter 4, 0 ; [EBP - 4] holds 4 byte temp variable
mov EBX, [EBP + 8] ; pointer to entire date string
lea ESI, [EBX] ; pointing to day part of date
lea EDI, [EBP - 4] ; pointing to address of local variable to store day string
mov ECX, 2
cld
rep movsb
mov EDX, 0
mov [EDI], EDX ; add null terminator
lea EDX, [EBP - 4]
mov EAX, sval(EDX) ; convert day string to int
push EAX ; push EAX to stack
; extract month from date
lea ESI, [EBX + 3] ; pointing to month part of date
lea EDI, [EBP - 4] ; pointing to address of local variable to store month string
mov ECX, 3
cld
rep movsb
mov EDX, 0
mov [EDI], EDX ; add null terminator
; debug print of month string
pushad
lea EDX, [EBP - 4]
print EDX
print chr$(9) ; print a tab character
print chr$(13,10)
popad
; find month number
sub ESI, ESI
lea EDX, [EBP - 4]
mov EAX, [EDX]
mov ECX, 12
search_top:
lea EDX, [months + ESI * 4]
mov EBX, [EDX]
inc ESI
cmp EAX, EBX
loopne search_top
mov EDX, ESI ; result is in ESI
pop EAX ; pop EAX off the stack
mov AH, DL ; copy the month int into AH
push EAX ; push EAX to stack
; convert year chars to 2 byte int
mov EBX, [EBP + 8]
lea ESI, [EBX + 7] ; pointing to year part of date
lea EDI, [EBP - 4] ; pointing to address of local variable to store year string
mov ECX, 4
cld
rep movsb
mov EDX, 0
mov [EDI], EDX ; add null terminator
lea EDX, [EBP - 4]
mov EDX, sval(EDX) ; convert year string to int
pop EAX ; pop EAX off the stack
mov EBX, EAX ; copy EAX (contains month in AH and day in AL) to EBX
mov EAX, EDX ; copy year to EAX
shl EAX, 16 ; shift the year over to high 16 bits in EAX
mov AX, BX ; copy the month and day into low 16 bits in EAX
;print EAX ; this crashes the proc
print str$(EAX)
print chr$(13,10)
leave
ret 4
exit

Answer 1

If your dates are stored in an array, and you want to use another array to store the dates converted to numbers, you will need at least one loop. You can use index registers (ESI, EDI) to point to both arrays, then use one register to read the value from one array, and the other register to move the value into the other array.
Let's imagine you already have next 3 procedures :
num2date : converts a num in EAX back into a date (the opposite of datetonum). This date is stored in a variable date that is declared like this : date BYTE "DD-MMM-AAAA".
bubble_sort : sorts the numbers in array ra.
transfer_date : takes the 11 bytes of variable date and move them into the position pointed by ESI (ESI is pointing somewhere inside array dates).
This could be the logic of your code :
start:
;▼ NEXT LOOP CONVERTS ALL DATES TO NUMBERS ▼
lea ESI, dates ;POINTER TO ARRAY "DATES".
lea EDI, ra ;POINTER TO ARRAY "RA".
mov ECX, 5 ;LENGTH OF ARRAY "DATES".
dates2numbers:
push ECX ESI EDI ;PRESERVE REGISTERS.
mov EAX, [ESI] ;CURRENT DATE.
push EAX
call datetonum ;CONVERT CURRENT DATE TO A NUMBER.
pop EAX ;GET THE NUMBER.
pop EDI ESI ECX ;RESTORE REGISTERS.
mov [EDI], EAX ;STORE NUMBER IN "RA".
add ESI, 12 ;NEXT ITEM IN ARRAY "DATES" (12 BYTES EACH).
add EDI, 4 ;NEXT ITEM IN ARRAY "RA" (4 BYTES EACH).
loop dates2numbers
call bubble_sort ;◄■■■ SORT ARRAY "RA".
;▼ NEXT LOOP CONVERTS ALL NUMBERS TO DATES ▼
lea ESI, dates ;POINTER TO ARRAY "DATES".
lea EDI, ra ;POINTER TO ARRAY "RA".
mov ECX, 5 ;LENGTH OF ARRAY "RA".
numbers2dates:
push ECX ESI EDI ;PRESERVE REGISTERS.
mov EAX, [EDI] ;CURRENT NUMBER.
call num2date ;CONVERTS EAX TO A DATE IN VARIABLE "DATE".
;VARIABLE "DATE" LOOKS LIKE THIS : DATE BYTE "DD-MMM-AAAA"
;"NUM2DATE" SHOULD PRESERVE ESI AND RESTORE IT
;BECAUSE "TRANSFER_DATE" WILL NEED IT.
call transfer_date ;TRANSFER CONTENT OF VARIABLE "DATE" INTO THE
;ARRAY "DATES" AT THE POSITION ESI IS POINTING TO.
pop EDI ESI ECX ;RESTORE REGISTERS.
add ESI, 12 ;NEXT ITEM IN ARRAY "DATES" (12 BYTES EACH).
add EDI, 4 ;NEXT ITEM IN ARRAY "RA" (4 BYTES EACH).
loop numbers2dates