Re: question related to hash

I perltidyd your program

#!/usr/bin/perl -w
use strict;
my ( $key, $value );
my %hash = (
    rat => "acggghhh",
    mat => "dhhdhdhdh",
    rat => "fhhfjfjj",
    rat => "dggdgdgdg"
);
while ( ( $key, $value ) = each %hash ) {
    print "$key and $value \n";
}
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is equivalent to

#!/usr/bin/perl -w
use strict;
my ( $key, $value );
my %hash = (
    rat => "acggghhh",
    mat => "dhhdhdhdh",
);
$hash{rat} = "fhhfjfjj";
$hash{rat} = "dggdgdgdg";
while ( ( $key, $value ) = each %hash ) {
    print "$key and $value \n";
}
[download]

That is how hash assignment works, duplicate keys overwrite the value. If you want to append to rat, you might write

$hash{rat} .= "fhhfjfjj";
$hash{rat} .= "dggdgdgdg";
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Comment on Re: question related to hash Select or Download Code

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Re^2: question related to hash by aanriot (Sexton) on Jun 24, 2011 at 11:19 UTC
Hash keys have to be unique, but you can use something like this: `#!/usr/bin/perl use strict; use warnings; my %hash=( rat=> [ "acggghhh", "fhhfjfjj", "dggdgdgdg" ], mat=> [ "dhhdhdhdh" ] ); foreach my $key (keys %hash) { print $key, "=", @{ $hash{$key} }, "\n"; }` [download]	[reply] [d/l]

Replies are listed 'Best First'.

Re^2: question related to hash
by aanriot (Sexton) on Jun 24, 2011 at 11:19 UTC

#!/usr/bin/perl

use strict;
use warnings;

my %hash=(
    rat=> [ "acggghhh", "fhhfjfjj", "dggdgdgdg" ],
    mat=> [ "dhhdhdhdh" ]
);

foreach my $key (keys %hash) {
    print $key, "=", @{ $hash{$key} }, "\n";
}
[download]

[reply]
[d/l]