Modify the Summation program attached as follows: Select
an array size using a constant:
ARRAY_SIZE = 20
array DWORD ARRAY_SIZE DUP(?)
Write a new procedure that prompts the user for the number of integers
to be processed. Pass the same value to the PromptForIntegers procedure.
How many integers wil be added? 19
TITLE Integer Summation Program (Sum2.asm)
; This program inputs multiple integers from the user,
; stores them in an array, calculates the sum of the
; array, and displays the sum.
INCLUDE Irvine32.inc
IntegerCount = 3 ; array size
.data
prompt1 BYTE "Enter a signed integer: ",0
prompt2 BYTE "The sum of the integers is: ",0
array DWORD IntegerCount DUP(?)
.code
main PROC
call Clrscr
mov esi,OFFSET array
mov ecx,IntegerCount
call PromptForIntegers
call ArraySum
call DisplaySum
exit
main ENDP
;-----------------------------------------------------
PromptForIntegers PROC
;
; Prompts the user for an array of integers, and fills
; the array with the user's input.
; Receives: ESI points to the array, ECX = array size
; Returns: nothing
;-----------------------------------------------------
pushad ; save all registers
mov edx,OFFSET prompt1 ; address of the prompt
L1:
call WriteString ; display string
call ReadInt ; read integer into EAX
call Crlf ; go to next output line
mov [esi],eax ; store in array
add esi,4 ; next integer
loop L1
L2:
popad ; restore all registers
ret
PromptForIntegers ENDP
;-----------------------------------------------------
ArraySum PROC
;
; Calculates the sum of an array of 32-bit integers.
; Receives: ESI points to the array, ECX = array size
; Returns: EAX = sum of the array elements
;-----------------------------------------------------
push esi ; save ESI, ECX
push ecx
mov eax,0 ; set the sum to zero
L1:
add eax,[esi] ; add each integer to sum
add esi,4 ; point to next integer
loop L1 ; repeat for array size
L2:
pop ecx ; restore ECX, ESI
pop esi
ret ; sum is in EAX
ArraySum ENDP
;-----------------------------------------------------
DisplaySum PROC
;
; Displays the sum on the screen
; Recevies: EAX = the sum
; Returns: nothing
;-----------------------------------------------------
push edx
mov edx,OFFSET prompt2 ; display message
call WriteString
call WriteInt ; display EAX
call Crlf
pop edx
ret
DisplaySum ENDP
END main
