Re^2: iterating through array and saving matches to new array

To make the the "or" of all 3 arrays with unique values > 850, consider this:

#!/usr/bin/perl
use strict;
use warnings;


my @b = 1..1000;
my @c = 900..1000;
my @d = 910..1000;
#  my @newb =  grep {$_>850}(@b&&@c&&@d);  ### will not  work!

my %seen;
my @newb = map{ ($_ > 850 and !$seen{$_}++) ?  $_: ()} (@b,@c,@d);

print "@newb\n";
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I am not sure what the intent here is.

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Re^3: iterating through array and saving matches to new array by AnomalousMonk (Archbishop) on Apr 19, 2018 at 21:32 UTC
Wouldn't the code be more readable/maintainable/etc with List::Util`::uniq()`: `my @newb = uniq grep $_ > 850, @b, @c, @d;` Results are the same per Test::More`::is_deeply()`. (In older Perls, see List::MoreUtils`::uniq`.) Give a man a fish: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^4: iterating through array and saving matches to new array by Marshall (Canon) on Apr 19, 2018 at 23:05 UTC
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.	[reply]
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: `<%-{-{-{-<`	[reply] [d/l]
Re^6: iterating through array and saving matches to new array by Marshall (Canon) on Apr 20, 2018 at 02:56 UTC
Re^7: iterating through array and saving matches to new array by AnomalousMonk (Archbishop) on Apr 21, 2018 at 20:16 UTC
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