Breaking out of nested for loop in batch file

Question

After coming across this issue twice I thought I would post it here to see if anyone knows how to get around it.

I can't seem to break out of nested loops using goto, because it looks like when it breaks out of the inner loop, the parentheses then don't match because it never reached the inner closing one.

I have narrowed this down to a very simple example

for %%a in (1,2,3) do (
for %%b in (4,5,6) do (
echo Breaking
goto :BREAK
)
:BREAK
)

This results in the error

) was unexpected at this time.

I thought maybe adding extra brackets might solve the issue but it won't help unless I know I am going to break, if it's a conditional break, it's the same problem.

Is there any easy alternative to breaking out of the inner loop back into the outer, even when it is a conditional break using if's and else's?

Answer 1

Break by placing inner loop in a label.

for %%a in (1, 2, 3) DO (

   call :innerloop 
)
:innerloop
for %%b in (4, 5, 6) DO (
  if %%b==<something> (
    echo    break
    goto :break
  )

)
:break

Answer 2

You may also omit the rest of iterations after the break with a controlling variable tied to the FOR:

@echo off
for %%a in (1,2,3) do (
   echo Top-level loop: %%a
   set break=
   for %%b in (4,5,6) do if not defined break (
      echo Nested loop: %%a-%%b
      if %%b == 4 (
         echo Breaking
         set break=yes
      )
   )
)

This method preserve the code of the nested for-body in its original place and allows to easily set breaks at more than one point inside the for-body.

Antonio