How do you use SETLOCAL in a batch file?

Question

How do you use setlocal in a batch file? I am just learning scripting and would like it explained to me in very simple terms.

I have a script that stops

Answer 1

Suppose this code:

If "%getOption%" equ  "yes" (
   set /P option=Enter option: 
   echo Option read: %option%
)

Previous code will NOT work becase %option% value is replaced just one time when the IF command is parsed (before it is executed). You need to "delay" variable value expansion until SET /P command had modified variable value:

setlocal EnableDelayedExpansion
If "%getOption%" equ  "yes" (
   set /P option=Enter option: 
   echo Option read: !option!
)

Check this:

set var=Before
set var=After & echo Normal: %var%  Delayed: !var!

Guess what the output is...