If they are very different, then a dispatch table or a Perl6 switch statement is about the most efficient.

If the code for all three cases is very similar, then perhaps this can be made to work for you:

if (m/key(\d)/) {
  # $1 contains the digit following "key"
  print "Found key followed by a $1\n"
  $count{$1}++;
  print "Total times this key was seen: ", $count{$1}, "\n";
  ...
}
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