This program just runs fine, but output is not correct
INCLUDE Irvine32.inc
.data
array BYTE 5,4,3,2,1
.code
main PROC
mov ecx,lengthof array
l1:
mov esi,0
mov eax,0
l2:
mov al,array[esi]
cmp al,array[esi+1]
jbe noswap
mov dl,array[esi+1]
mov array[esi+1],al
mov array[esi],dl
noswap:
add esi,1
cmp esi,ecx
jne l2
loop l1
mov esi,0
mov esi,offset array
mov ecx,lengthof array
mov ebx,type array
call dumpmem
exit
main ENDP
END main
It gives the following output: 00 01 02 03 04
It is not showing 5 at the end. I think there is a problem in looping
In your code, ecx will start out at lengthof array (which is 5), and will go down to 1 (the loop instruction won't jump back to l1 when ecx becomes 0). This leads to problems in the inner loop: the first is that esi will never become 0, so you'll never be comparing the elements at positions 0 and 1; the other is that you'll be comparing the elements at positions 4 and 5 during the first iteration of l1. The array only has 5 elements, so position 5 is past the end of the array, since the positions are zero-based.
You should instead initialize ecx to (lengthof array)-1. If MASM doesn't like that syntax, use lengthof array and put a dec ecx on the next line.
And the loop l1 line should be changed to dec ecx followed by jns l1. That way ecx will go from 4..0, instead of from 5..1.