in reply to Auto-filling an array

And then there's

my @list;
push(@list, 'N/A') for (1..14);

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Perl's push, pop, shift and unshift are extremely efficient. They don't copy the entire array, unlike @list=('N/A')x14. In addition, for (a..b) is also very efficient. It is optimised to not create a list, unlike ('N/A')x14.

That said, I like the idea of leaving the array undefined, and replacing each undef with "N/A" when printing.

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Re^2: Auto-filling an array
by tlm (Prior) on Mar 28, 2005 at 23:39 UTC

    I was very intrigued by ikegami's post, so I went ahead and benchmarked the two approaches: 

    use Benchmark 'cmpthese';
cmpthese( -1,
          { x    => sub { my @list = ( 'N/A' ) x 14 },
            push => sub { my @list; push @list, $_ for 1 .. 14 } }
        );



          Rate times  push
x      89321/s    --  -23%
push  115925/s   30%    --

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    Where would I be without Benchmark?

    the lowliest monk

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[d/l]
Re^2: Auto-filling an array
by nimdokk (Vicar) on Mar 28, 2005 at 19:13 UTC
    I actually tried putting the 'N/A's in when I was writing the list, but the data was not coming back right, so I went with a more brute force approach. That said of course. I'm going to be looking at other ways to tighten this script up.
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