Check if variables are not empty strings in bash with a reverse case switch statement

I have a number of variables and for each one I need to do the following:
If the variable is "", do nothing
If the variable isn't "", then echo "text $var".

Each variable will need to send different piece of text.

The way I would like to do this would be with case statements.
Normally they work like this:

case $var in
  a)
    echo "a"
  ;;
  *)
  ;;
esac

However, I would like it to work like this:

case !"" in

  $var1)
    echo "var1"
    ;;&
  $var2)
    echo "var2"
    ;;&
esac

If the expression is "" or something like "1" then it can be compared with the variables successfully. But it doesn't accept !"" or other variations of not "" that I can think of so it doesn't work.

I could do this with several if statements, a function or a for loop iterating over the variables. But I can't see a way to do it with only case.

You can't exclude certain values from the case by using not. Instead, match on those that shouldn't result in any action too, and, do nothing if you get a match.

In this example, "" and "#" will result in doing nothing. I've used ;& to let "" fallthrough to "#" just to be able to log that it's doing nothing for both of them.

#!/bin/bash

var=$1
var1=a
var2=b

case $var in
  "$var1")
    echo "text var1"
    ;;
  "$var2")
    echo "text var2"
    ;;
  "")
    ;&
  "#")
    echo "doing nothing"
    ;;
  *)
    echo "doing the default thing"
    ;;
esac

You can do this with an alternate value expansion: ${var1:+x} will expand to "x" if the variable is set to a non-empty value, and "" otherwise. So something like this should work.

case "x" in
        ${var1:+x}) echo "$var1" ;;&
        ${var2:+x}) echo "$var2" ;;&
        ${var3:+x}) echo "$var3" ;;&
esac

But I'd consider this an ugly hack, and prefer a function or something similar as a cleaner solution.