Windows Batch Variable within variable

问题

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.

回答1:

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!

回答2:

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%

回答3:

Are you after something like this?

cls
@echo off
setlocal EnableDelayedExpansion
Set num=5
Set "c!num!=test"
Echo !c5!

See http://ss64.com/nt/delayedexpansion.html for more info on delayed expansion.

cls
@echo off
setlocal EnableDelayedExpansion
set num=4
set c1=this is a demo
set c2=second example
set c3=third
set c4=this is the one I want
set c5=last
Echo !c%num%!

来源：https://stackoverflow.com/questions/27114936/windows-batch-variable-within-variable

标签

variables

batch-file