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Windows Batch Variable within variable

In windows batch could you set a variable within a variable?

Explained:

So the %num% is within the variable.

set num=5
set cnum=test
set h1=%c%num%%

Is it possible to make the percents work like parenthesis? The output should be h1=test

Any help would be appreciated.

like image 200
Strictly No Lollygagging Avatar asked Nov 24 '14 21:11

Strictly No Lollygagging


2 Answers

Your example in your question is a mess, but I think I understand what you are looking for:

@echo off
setlocal

set C1=apple
set C2=orange
set C3=banana

set num=2


:: Inefficient way without delayed expansion
:: This will be noticeably slow if used in a tight loop with many iterations
call echo %%C%num%%%

:: The remaining methods require delayed expansion
setlocal enableDelayedExpansion

:: Efficient way 1
echo(
echo !C%num%!

:: Efficient way 2 - useful if inside parenthesized block
:: where %num% will not give current value
echo(
for %%N in (!num!) do echo !C%%N!

:: Showing all values via a loop
echo(
for /l %%N in (1 1 3) do echo !C%%N!
like image 119
dbenham Avatar answered Nov 14 '22 10:11

dbenham


You may be looking for the Call Set command. This sets cnum to string c1, c2, c3 etc. It changes each time %num% changes. You can then use Call Set to assign any variable (h1 for example) to the value of the variable cnum stands for.

@echo off
setlocal enabledelayedexpansion
    set c5=test
    set num=5

    :: set cnum to string "c5"
        set cnum=c%num%
    :: set h1 to to the existing variable c5 
        call set "h1=%%%cnum%%%"
        echo %h1%
like image 40
sjoy Avatar answered Nov 14 '22 11:11

sjoy