3

I have following code:

@echo off
SET ITER=0
for %%i in (%*) do (
  SET ITER+=1
  ECHO %ITER%
)

The output is (for three arguments):

0
0
0

Expected output:

1
2
3

Why can't I access the updated variable in the for loop?

1

1 Answer 1

5

Expansion of variables with percents is done before a statement/block is executed.
So in your case the complete block is expanded before the echo %ITER% is executed, to constant echo 0.
The variable ITER itself is updated in the loop properly.

To avoid this, you could use the delayed expansion, this works like percent expansion but just in the moment of execution

@echo off
setlocal EnableDelayedExpansion
SET ITER=0
for %%i in (%*) do (
  SET /a ITER+=1
  ECHO !ITER!
)
Sign up to request clarification or add additional context in comments.

2 Comments

Ok, it's the line SET ITER+=1, this has to be SET /A..., else it can't calculate
Sorry, /A was missing for SET. Thanks!

Start asking to get answers

Find the answer to your question by asking.

Ask question

Explore related questions

See similar questions with these tags.