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Returning Local Variables

How to pass return values over the ENDLOCAL barrier?

Description: The question is: When localizing a function via SETLOCAL and ENDLOCAL, how to return a value that was calculated before executing ENDLOCAL when ENDLOCAL restores all variables back to its original state?
The answer comes with "variable expansion". The command processor expands all variables of a command before executing the command. Letting the command processor executing ENDLOCAL and a SET command at once solves the problem. Commands can be grouped within brackets.
Script: Download: BatchTutoFunc5.bat  
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 @echo off

set "aStr=Expect no changed, even if used in function"
set "var1=Expect changed"
echo.aStr before: %aStr%
echo.var1 before: %var1%
call:myGetFunc var1
echo.aStr after : %aStr%
echo.var1 after : %var1%

echo.&pause&goto:eof

::--------------------------------------------------------
::-- Function section starts below here
::--------------------------------------------------------

:myGetFunc    - passing a variable by reference
SETLOCAL
set "aStr=DosTips"
( ENDLOCAL
    set "%~1=%aStr%"
)
goto:eof

:myGetFunc2    - passing a variable by reference
SETLOCAL
set "aStr=DosTips"
ENDLOCAL&set "%~1=%aStr%"       &rem THIS ALSO WORKS FINE
goto:eof
Script Output:
 DOS Script Output 
aStr before: Expect no changed, even if used in function
var1 before: Expect changed
aStr after : Expect no changed, even if used in function
var1 after : DosTips

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