in reply to Re^3: iterating through array and saving matches to new array
in thread iterating through array and saving matches to new array

Yes, actually it would be. Although I would still prefer the block form of grep.
I show how to use map{}

It actually took me quite a while to learn how to return "nothing" instead of "undef" from a map.

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Re^5: iterating through array and saving matches to new array
by AnomalousMonk (Archbishop) on Apr 20, 2018 at 01:29 UTC
    ... how to return "nothing" instead of "undef" from a map.

    That is a bit tricky :)

    Give a man a fish:  <%-{-{-{-<

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[d/l]
      I use grep to get a subset of an array.
      I use map to transform an array into another array.
      Special syntax for map can be used to do both, in certain situations.

      UPDATE: I have now forgotten the exact code that I used to "return nothing", but something like this (untested) should work: 

      map{some condition ? $val : ()}@array;

      [download]
      This () is not "undefined", it is absolutely nothing. Of course it it possible to combine map and grep to filter out undefined values. I remember doing this for some reason, but it's been a few years. If someone wants to do this, just knowing that it is possible will get you started. perl doc map for more info.
[reply]
[d/l]

        c:\@Work\Perl\monks>perl -wMstrict -MData::Dump -le
"my @ra = (1 .. 5);
 ;;
 my @rb = map { $_ == 3 ? () : $_ } @ra;
 dd \@rb;
"
[1, 2, 4, 5]

        [download]

        Give a man a fish:  <%-{-{-{-<

[reply]
[d/l]
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