Clever Geek Handbook

Why does the first hash value disappear in Perl?

Why apple:2

does the hash remove the first value when printing the output?

use warnings;
use strict;
use Data::Dumper;

my @array = ("apple:2", "pie:4", "cake:2");
my %wordcount;
our $curword;
our $curnum;
foreach (@array) {
    ($curword, $curnum) = split(":",$_);
    $wordcount{$curnum}=$curword;
}
print Dumper (\%wordcount);
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2 answers


Perl hash can only have unique keys, so

$wordcount{2} = "apple";


later overwritten

$wordcount{2} = "cake";
+8


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What you probably wanted to do is:

use warnings;
use strict;

use Data::Dumper;

my @array = ("apple:2", "pie:4", "cake:2");
my %wordcount;
for my $entry (@array) {
    my ($word, $num) = split /:/, $entry;
    push @{$wordcount{$num}}, $word;
}

print Dumper (\%wordcount);

Thus, each entry in the %wordcount

bindings a number of words to an array of words that appear many times (assuming the symbol :n

in the notation indicates the number).



It's okay to be a beginner, but it's not okay to assume that other people can read your mind.

Also, don't use globals ( our

) with lexical scope ( my

).

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