Question

I’m trying to handle an input argument when I do call script.bat argument
If argument is missing, the receiving script.bat will pop a prompt to ask user to assign value. But right now even if I do script.bat number, the prompt shows up anyway…not sure why.

Code:

:Loop
IF "%1"=="" GOTO Prompt
  set VAR=%1
SHIFT
GOTO Loop
:Prompt
  set /p VAR="Check which value? "
  GOTO Continue
:Continue

Answer 1

You need to skip the :Prompt if the argument was supplied correctly:

:Loop
IF "%1"=="" GOTO Prompt
  SET VAR=%1
  GOTO Continue
SHIFT
GOTO Loop
:Prompt
  set /p VAR="Check which value? "
  GOTO Continue
:Continue

Actually, you can now remove the SHIFT and GOTO Loop; as @dbenham posted in the comment below, it’s unreachable code. This also eliminates the :Loop itself, as it is never used. This reduces it to:

IF "%1"=="" GOTO Prompt
  SET VAR=%1
  GOTO Continue
:Prompt
  set /p VAR="Check which value? "
  GOTO Continue
:Continue