How to make a loop in assembler?

Question

assembler

Here is my code

.386
.model flat, stdcall
option casemap: none

include \masm32\include\kernel32.inc
include \masm32\include\masm32.inc

includelib \masm32\lib\kernel32.lib
includelib \masm32\lib\masm32.lib

.data
  msg1 db "Please, enter String: ",0, 13
  numberOfChanges db 0

.data?
  buffer db 256 dup(?)

.code

start:
  push offset msg1
  call StdOut
  
  push 256
  push offset buffer
  call StdIn
  
  mov edi, offset buffer
  mov al, "a"
  repne scasb
  mov al, "b"
  inc numberOfChanges
  mov byte ptr[edi-1], "b"
  
  push offset buffer
  call StdOut
  
exit:
  push 0
  call ExitProcess

End start

It is necessary to loop the replacement of letters, this program changes only 1 encountered letters a
I also can’t figure out how to increment the replacement counter and output it along with the changed string

Answer 1

You need to use conditional jumps.