Why it's stupid to 'use a variable as a variable name' 
my %GROUPS => (
    A => 1,
    B => 2,
    C => 3
);


my %FOO = (
    A => {
        1 => x,
        2 => y,
        3 => z
    },
    B => {
        1 => x,
        2 => y,
        3 => z
    },
);

for my $group (keys %GROUPS) {
    my $foo = $FOO{$group};

    for (keys %$foo) {
        print("$_ in group $group: $foo->{$_}\n");
    }
}

[download]

But why does %GROUPS have values that aren't used? You probably want: 

my %GROUPS => (
    A => {
        1 => x,
        2 => y,
        3 => z
    },
    B => {
        1 => x,
        2 => y,
        3 => z
    },
);

for my $group (keys %GROUPS) {
    my $foo = $GROUPS{$group};

    for (keys %$foo) {
        print("$_ in group $group: $foo->{$_}\n");
    }
}

[download]

In reply to Re: hash and constants by ikegami
in thread hash and constants by Anonymous Monk

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