Re: array pre-allocation trick

Thank you for your ideas. I realize that I could keep the variable in an outer scope, but what I was trying to do was preallocate space without having it filled up with undefs, so I could use push on the array. My example code should have included a loop like the following inside the subroutine after the "Push stuff on the array here" comment:

for (1..5000) {
  push @array,$_;
}
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Re: Re: array pre-allocation trick by rir (Vicar) on Oct 31, 2002 at 04:41 UTC
I apologize, I didn't read that comment strictly enough. No, push is going to grow your array. Try something like: `for ( 0..4999) { $array[$_] = $_; }` [download] Although if you really are really tight, you may want to test if a while or C-style loop is faster than building the list of integers.	[reply] [d/l]
Re^2: array pre-allocation trick by Aristotle (Chancellor) on Oct 31, 2002 at 19:22 UTC
Sounds like you want to have a look at the map function, actually. `my @array = map { do_stuff_with($_); $_ } 1 .. 5000;` Makeshifts last the longest.	[reply] [d/l]