Using goto with a bunch if conditions is deemed inefficient. You either use goto or if statements on its own sparingly. If I were you, I'd use goto in this fashion:

alias test {
  goto $iif(!$1,$null,$iif($1 = 2,yes,no))
  :no
  echo -a blah!
  halt
  :yes
  echo -a Aha!
  halt
  :error
  echo -a * You didn't specify a number 1 or something else!
  reseterror
}

You can put :yes or :no anywhere in the script. Goto jumps from point B to point A and vice versa.