How to set BATCH if statement to select random predefined variables? - windows

Question

How do I set my if statement to call on different predefined variables based on user input.
Example 1 is red 2 is orange 3 is blue 4 is random.
If user puts 1 they get red. If they put 2 they get orange. If they put 3 they get blue. If they put 4 they get either red, orange, or blue.

Answer 1

The following script shows one way of doing it, using arrays of colors and a method for doing double expansion on a variable (allowing for array access):
#setlocal enableextensions enabledelayedexpansion
#echo off
set color[1]=red
set color[2]=orange
set color[3]=blue
:loop
set /p inp="Enter a number [1=red, 2=orange, 3=blue, 4=random]: "
if "%inp%"=="4" set /a "inp = %RANDOM% %% 3 + 1"
call set color=%%color[%inp%]%%
if "%color%"=="" goto loop
endlocal && set color=%color%
For a more generalised solution, you can look at the following script, which better handles the prompting for arbitrary colors:
#setlocal enableextensions enabledelayedexpansion
#echo off
rem Clear out all color variables then create array.
set color=junk
for /f "delims==" %%a in ('set color') do set %%a=
set /a "count = 0"
set /a "count = count + 1" && set color[!count!]=red
set /a "count = count + 1" && set color[!count!]=orange
set /a "count = count + 1" && set color[!count!]=blue
set /a "count = count + 1" && set color[!count!]=green
set /a "next = count + 1"
rem Loop until color is valid.
:loop
echo.Choices:
for /l %%a in (1,1,%count%) do (
set value=!color[%%a]!
echo. %%a. !value!
)
echo. %next%. Random choice from above
set /p inp="Enter a number: "
rem set inp=1
rem Special handling, choose random value
if "%inp%"=="%next%" set /a "inp = %RANDOM% %% count + 1"
call set color=%%color[%inp%]%%
if "%color%"=="" goto loop
rem Exit local scope, "leaking" color value.
endlocal && set color=%color%

Answer 2

#ECHO Off
SETLOCAL
SET "choices=1=red 2=blue 3=green 4=random"
SET /p inp="[%choices%]: "
FOR /f %%a IN ('echo %choices: =^&echo %') DO SET /a maxchoice=%%a
IF "%inp%"=="%maxchoice%" SET /a inp=%RANDOM% %% (maxchoice - 1) +1
FOR /f "tokens=1,2" %%a IN ('echo %choices: =^&echo %') DO IF "%%a"=="%inp%" SET "hue=%%b"
ECHO %hue%
GOTO :EOF
Here's my version. All you need to do is follow the bouncing ball setting up choices and ensure that random is the last selection.

Answer 3

I started to write a comment as reply to new paxdiablo's solution, but it becomes too large, so I prefer to write my own solution here with all those points included:
#echo off
setlocal EnableDelayedExpansion
rem Create the color array
set n=0
for %%a in (red orange blue green) do (
set /A n+=1
set color[!n!]=%%a
)
set /A next=n+1
rem Show the available colors menu
echo Choices:
echo/
for /L %%i in (1,1,%n%) do echo %%i. !color[%%i]!
echo %next%. Random choice from above
echo/
rem Loop until color is valid
:loop
set /P "inp=Enter a number: "
if "%inp%" equ "%next%" set /A inp=%random% %% n + 1
set color=!color[%inp%]!
if "%color%" equ "" goto loop
echo/
echo Color: %color%