what I can do?

[dgonzalez]

I want to make a array with data entered from the keyboard, but when I am going to print it in screen, it shows something totally different, How I can correct this?

.486                                    ; create 32 bit code
    .model flat, stdcall                    ; 32 bit memory model
    option casemap :none                    ; case sensitive

    include \masm32\include\windows.inc     ; always first
    include \masm32\macros\macros.asm       ; MASM support macros

    include \masm32\include\masm32.inc
    include \masm32\include\gdi32.inc
    include \masm32\include\user32.inc
    include \masm32\include\kernel32.inc

    includelib \masm32\lib\masm32.lib
    includelib \masm32\lib\gdi32.lib
    includelib \masm32\lib\user32.lib
    includelib \masm32\lib\kernel32.lib

    .data?
     vn   DD  4 dup (?)
    .code                       ; Tell MASM where the code starts

    start:                          ; The CODE entry point to the program
      call main                   ; branch to the "main" procedure
    exit

; «««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««

    main proc
        LOCAL cnt   :DWORD          ; allocate a loop counter
        LOCAL str1  :DWORD
        LOCAL str2  :DWORD
        LOCAL var   :DWORD

        mov esi, vn
        mov cnt,4
        jmp ciclo

    ciclo:
        mov str1, input("type values of array: ")
        print chr$(" ",10,13)
        mov var, sval(str1)
        print chr$(" ",10,13)
        mov eax,var
        mov vn[esi],eax
        add esi,4
        sub cnt, 1
        cmp cnt,0
        ja ciclo
        je imprime

    imprime:
        mov cnt,4
        mov esi,vn
        jmp cimprime
    cimprime:
        mov eax,vn[esi]
        print str$(eax)
        print chr$(" ",10,13)
        print chr$("the values of array are: ")
        print chr$(" ",10,13)
        add esi,4
        sub cnt,1
        cmp cnt,0
        ja cimprime
        je sale         

    sale:
        ret

    main endp


end start                 

[rags]

One thing I see is right after your local declarations in the main proc, you have this:

Code Select Expand


        mov esi, vn
        mov cnt,4
        jmp ciclo

    ciclo:

AT this point in time vn will contain garbage, because it is unitialized.
declaring a variable n the DATA? section as an un-initialized variable does not garentee it will contain a zero.

Secondly why the jmp ciclo, when that is the address immediately following the jmp statement? The jump is not needed.
Hope this helps.

Rags

[dgonzalez]

thank you rags!!

I already made some changes, but when I want to show the array in the screen, the continuous problem, it's no shows zeros (0) but very rare values.

Code Select Expand


.486                                    ; create 32 bit code
    .model flat, stdcall                    ; 32 bit memory model
    option casemap :none                    ; case sensitive

    include \masm32\include\windows.inc     ; always first
    include \masm32\macros\macros.asm       ; MASM support macros

    include \masm32\include\masm32.inc
    include \masm32\include\gdi32.inc
    include \masm32\include\user32.inc
    include \masm32\include\kernel32.inc

    includelib \masm32\lib\masm32.lib
    includelib \masm32\lib\gdi32.lib
    includelib \masm32\lib\user32.lib
    includelib \masm32\lib\kernel32.lib

    .data
     vn   DD  4 dup (?)
    .code                       ; Tell MASM where the code starts

    start:                          ; The CODE entry point to the program
      call main                   ; branch to the "main" procedure
    exit

; «««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««««

    main proc
        LOCAL cnt   :DWORD          ; allocate a loop counter
        LOCAL str1  :DWORD
        LOCAL str2  :DWORD
        LOCAL var   :DWORD
        LOCAL tm   :DWORD


        mov esi, vn
        mov cnt,4
       
    ciclo:
        mov str1, input("type values of array: ")
        print chr$(" ",10,13)
        mov var, sval(str1)
        print chr$(" ",10,13)
        mov eax,var
        mov vn[esi],eax
        add esi,4
        sub cnt, 1
        cmp cnt,0
        ja ciclo
        je imprime

    imprime:
        mov cnt,4
        mov esi,vn
        jmp cimprime
    cimprime:
        mov eax,vn[esi]
        mov tm, eax
        print str$(tm)
        print chr$(" ",10,13)
        print chr$("the values of array are: ")
        print chr$(" ",10,13)
        add esi,4
        sub cnt,1
        cmp cnt,0
        ja cimprime
        je sale         

    sale:
        ret

    main endp


end start           




[attachment deleted by admin]

[rags]

This does not make vn equal to zeros, if that is what you want:

Code Select Expand


    .data
     vn   DD  4 dup (?)


That statement should be in the .data? section.
If you have a variable that must be equal to some value at startup, then declare it in the .data section.
Here is an example:
Suppose you have a variable named 'wheels' and want it to be equal to 4 at startup.
This is what it would look like in the program listing:

Code Select Expand


        .DATA
        wheels dd 4


You still have jumps in your code that are not needed.
You do not have to 'jump' to the address immediately after a jump statement if that is where the program flow will take it anyway.
Example:

Code Select Expand


       xor ecx, ecx      ; zeroes the ecx register
Again:
        add ecx, 5
       cmp ecx, 15
       jne Again          ; when the condition ecx =15 is met, program flow continues at the done label
                              ; otherwise program execution branches back to the Again label.
Done:
      ret




rtegards,

Rags