Batch File - Get list value using index key - batch-file

Question

I have written a script to bat file that will print the random value from list.
but I am facing problem to access list value using it's index
My code is:
set list=A B C D a b c
echo %list[3]%
for /l %%a in (1,1,6) do (
#set /a bottomlimit = 0
#set /a upperlimit = 5
#set /a num = !bottomlimit! + !RANDOM! %% !upperlimit! - !bottomlimit! + 1
echo %list[!num!]%
TIMEOUT /T 5
)
Waiting for your valuable solution.

Answer 1

Just three options. Number one to handle your approach. Number two for a "pure" array in environment variables. Number three will mix the two, definition of the list as in option 1, but iterating the list to generate the array in option 2.
#echo off
setlocal enableextensions enabledelayedexpansion
REM OPTION 1 - The list
echo -------------------------------------------------
setlocal
set "list=A B C D a b c"
set /a bottomlimit=0
set /a upperlimit=6
for /l %%a in (1,1,6) do (
set /a "num=!bottomlimit! + ( !RANDOM! %% (!upperlimit! - !bottomlimit! + 1))"
set "pos=0"
for %%l in (!list!) do if defined pos if !pos!==!num! ( echo %%l & set "pos=" ) else ( set /a "pos+=1")
)
endlocal
REM OPTION 2 - The "pure" array
echo -------------------------------------------------
setlocal
set "list[0]=A"
set "list[1]=B"
set "list[2]=C"
set "list[3]=D"
set "list[4]=a"
set "list[5]=b"
set "list[6]=c"
set /a bottomlimit=0
set /a upperlimit=6
for /l %%a in (1,1,6) do (
set /a "num=!bottomlimit! + ( !RANDOM! %% (!upperlimit! - !bottomlimit! + 1))"
for %%n in (!num!) do echo !list[%%n]!
)
endlocal
REM OPTION 3 - The remix
echo -------------------------------------------------
setlocal
set "list=A B C D a b c"
set "pos=0"
for %%l in (!list!) do ( set "list[!pos!]=%%l" & set /a "pos+=1" )
set /a "bottomlimit=0"
set /a "upperlimit=!pos!-1"
for /l %%a in (1,1,6) do (
set /a "num=!bottomlimit! + ( !RANDOM! %% (!upperlimit! - !bottomlimit! + 1))"
for %%n in (!num!) do echo !list[%%n]!
)
endlocal
endlocal
exit /b

Answer 2

#echo off
setlocal EnableDelayedExpansion
set list=A B C D a b c
set /a counter=1
for %%a in (%list%) do (
set "list[!counter!]=%%~a"
set /a counter=counter+1
)
set list[
for /l %%a in (1,1,6) do (
#set /a bottomlimit = 0
#set /a upperlimit = 5
#set /a num = bottomlimit + !RANDOM! %% upperlimit - bottomlimit + 1
for %%# in (!num!) do echo !list[%%#]!
TIMEOUT /T 5
)
endlocal

Answer 3

You may use echo/%list:~3,1%, but you can't use echo/%list:~%num%,1%
Try this:
#echo off
set "list=ABCDabc"
echo/%list:~3,1%
set /a bottomlimit = 0
set /a upperlimit = 5
for /l %%a in (1,1,6) do (
CALL:CALC
CALL _temp.bat
Timeout /t 5
)
del _temp.bat
pause >nul
exit/b
:CALC
set /a num = %bottomlimit% + %random% %% %upperlimit% - %bottomlimit% + 1
echo/set "list=%list%">_temp.bat
echo/echo/%%list:~%num%,1%%>>_temp.bat
exit/b