计算数组中数字之间的差异（Assembly，Irvine）

Question

I'm trying to calculate the gaps between the numbers. For that purpose I'm using 2 arrays. So everything works fine except output and strange symbols that appears after the numbers.

first number-number in array at this moment, 2nd-different between elements, 3d- 2nd that already moved to the second array. Output: 1 2 2 /3 44/722/9one/
2

From where this symbols? What cause it? Wrong register? And why in the first loop 'gap'(array) has right numbers,but when I go through this array later it has just 2 and wired symbol?

INCLUDE Irvine32.inc

.data
array byte 1,3,7,9
gap byte ?
blank byte ' '
ph byte "Done",0

.code
main PROC
        mov eax,0
        mov ecx,lengthof array  
        mov esi, offset array
        mov edi,offset gap
         arr:

         mov al,[esi]
         call writedec; here

         .if ecx==1
         mov edx,offset ph 
         call writestring
         .else
         mov al,blank
         call writechar

            mov al,[esi+1]
            sub al,[esi]

            call writedec; here

            mov [edi],al

            ;check block
            mov al,blank
            call writechar
            mov al,[edi] ; here
            call writedec
            mov al,blank
            call writechar

             inc esi
             inc edi        
           .endif

           mov al,'/'
         call writechar

         loop arr

        call crlf  

         mov eax,0
         mov ecx,lengthof gap
         mov esi,offset gap

         go:

         mov al,[esi]
         call writedec
         mov al,blank
         call writechar
         inc esi
         loop go

         exit

main ENDP



myexit proc

              call waitmsg
              ret
      myexit endp

end main

Thank you!

Answer 1

Gotcha! the variable gap was wrong initialize.

This is the right initialization gap byte lengthof array-1 dup(?)