in reply to Re: Compare two arrays
in thread Compare two arrays

Why can't this work?
...
for my $filename (@file) {

   next unless $filename =~ /^\d+/;

   if(grep { %seen{$_} =~ $filename} keys %seen) {
     print " $filename\n";
    } else {
      print "$filename is not in array\n";
    }
}

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Re^3: Compare two arrays
by Eily (Monsignor) on Oct 01, 2014 at 17:25 UTC

    %seen{$_} is incorrect, you're only accessing one element (ie: a scalar) so you have to use the sigil $: $seen{$_}

    Now, look at your dump of \%test, you'll see that the value in $seen{$_} is actually an array, not a string, unless you have changed your data structure since the first post.

    Now your grep test (if I ignore your previous errors), applied to 96329XY and 96329XY_K.txt would turn into : "96329XY" =~ /96329XY_K.txt/, you probably have the wrong order. And you probably want to use quotemeta: grep { $filename =~ /\Q$_/ } keys %seen.

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[d/l]
[select]
      I tested like this:
      ...
for my $filename (@file) {
  
   #next unless $filename =~ /^\d+/;
   #if(grep { $seen{$_} =~ $filename} keys %seen) { # Failed
   #if(grep { $filename =~ $seen{$_} } keys %seen) { # Failed
   
if(grep { $filename =~ /\Q$_/ } keys %seen) {
     print " YES - $filename\n";
    } else {
      print " NO  - $filename\n";
    }
}

      [download]
      Why would it only work using "quotemeta"? I even removed the
      "next unless $filename =~ /^\d+/;

      Thanks for you time!
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[d/l]
[select]

        quotemeta (the \Q in the regex) makes sure that perl tries to find the string exactly as it is in $filename. If you don't use it, it will "translate" any meta character into its regex meaning. In your case, it probably does the same though.

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