Boolean - Output displays extra commas

[Klaus]

I'm looking for a solution that allows me to have multiple boolean selections and what ever is in a true state will output this into a comma delimited output. Anything that is set to false shows doesn't included the comma.

#set($1STRING='')
#if ($param1STRING=="true")
  #set($1STRING='1STRING')
#elseif ($param1STRING=="false")
  #set($1STRING='')
#set($2STRING='')
#if ($param1STRING=="true")
  #set($2STRING='2STRING')
#elseif ($param2STRING=="false")
  #set($2STRING='')
#end  
#set($3STRING='')
#if ($param3STRING=="true")
  #set($3STRING='1STRING')
#elseif ($param1STRING=="false")
  #set($1STRING='')
||$1STRING, $2STRING, $3STRING |

This is the output that I would like to have:

1STRING,2STRING,3STRING

This is an output that I can do not want. When a boolean option is not selected. It display an unnecessary comman.

1STRING,,3STRING

[Kirstin Seidel-Gebert]

I don't know what you need this for, but you could just add the comma to the strings itself (if they're not empty) instead of outputting "$1STRING,". This leads to the fact, that no comma will be displayed, if $2STRING is empty.

Cheers,
Kirstin