note stephen A transitory variable is a variable that isn't used for anything other than to schlep data from one line to another. (I'm not sure the term is right, but I think it's what you mean. I call 'em "useless variables", myself.) In other words, if I'm going to say: <code> my $foo = get_foo(); do_something($foo); </code> Then <code>$foo</code> is a transitory variable. It would be just as simple, and less error-prone, to say: <code> do_something( get_foo() ); </code> Why? Because variables can and should vary. It doesn't seem like such a big deal when the assignment and the use of the variable are right next to each other, but what if they get separated? <code> my $foo = get_foo(); if ($snargle = 3 && $foo = 2) { whatever($snargle, $foo); # lots of other stuff here... } do_something($foo); </code> Oops, on line 2 up there we changed the value of <code>$foo</code>. Also, it makes refactoring harder-- what if you wanted to pull out the stuff inside the if statement into its own subroutine? It'd be simpler if you didn't have <code>$foo</code> there at all, and just called <code>get_foo()</code> when you needed a foo-value. In your code, <code>@for_data</code>, <code>@map_data</code>, <code>@sort_data</code>, and <code>@grep_data</code> are all transitory variables. Ironically, <code>@last_elements</code> is not... you're using it to collect elements! Nothing wrong with that. As for why <code>slce_with_sort()</code> and <code>slice_with_grep()</code> aren't doing what you expect, it's because sort and grep don't do what you apparently think they do. :) The block argument to grep is a test block, not a filter block. So the statement <code> grep { $_->[2] } @slice_me; </code> means, "If the item at index 2 of <code>@$_</code> evaluates to true, return <code>$_</code>." The last bit is important-- it doesn't return the item at index 2, it returns the whole thing. A similar thing is happening with sort. You're sorting each row based on the value of the last column, and returning a list of the rows. Since the values are identical, it doesn't even change their order. :) So where did you get that water? Sounds like powerful stuff. :) stephen 161836 161836