Spidy has asked for the wisdom of the Perl Monks concerning the following question:

I solved the problem before this node was approved, please reap.

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Greetings Fellow Monks,

I have an array, that is filled with a number of elements. For example:

my @array = qw(penny coin dutch);

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And I want to delete the 'coin' entry, while only having the 'coin' value(not the index number of that element within the array). Does anyone know how exactly I'd do this?


Thanks,
Spidy
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Re: Deleting Elements from an Array without their Index Number?
by Corion (Patriarch) on Jul 23, 2006 at 21:19 UTC

    Do you want to remove coin from the array?

    my @not_coin = grep { $_ ne 'coin' } @array;

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    Or do you want to replace coin by undef?

    my @not_coin = map { $_ eq 'coin' ? undef : $_ } @array;

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[d/l]
[select]

      And of course you could also use grep to determine the index if you later would like to use it to remove elements with splice. 

      my @coin_idx = grep { $array[ $_ ] eq 'coin' } 0..$#array;

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[d/l]

      I like how writing these as map+ternary makes it obvious that grep is just a specialization of map.

      my @not_coin = map { $_ eq 'coin' ? () : $_} @array;
# Or do you want to replace coin by undef?
my @not_coin = map { $_ eq 'coin' ? undef : $_} @array;

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      ⠤⠤ ⠙⠊⠕⠞⠁⠇⠑⠧⠊

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[d/l]
        And map is a specialization of foreach+push. 
        my @not_coin;
foreach (@array) {
   push(@array, $_ eq 'coin' ? () : $_);
}

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        How does this help?
[reply]
[d/l]

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