I have the below hash structure, hash of hash.
$VAR1 = { '191' => { 'test1' => { 'score' => '9.18' }, 'test2' => { 'score' => '2.84' },
'test3' => { 'score' => '15.62' }, 'test4' => { 'score' => '11.84' },
'190' => { 'test1'=> { 'score' => '13.28' }, 'test2' => { 'score' => '-47.56' },
'test3' => { 'score' => '18.50' }, 'test4' => { 'score' => '14.88' } } }
I am trying to sort the hash based on the 'score' value. The sorting should happen only among whats inside of the main keys '191' and '190' . See below hash structure for expected result.
$VAR1 = { '191' => {'test3' => { 'score' => '15.62' }, 'test4' => { 'score' => '11.84' }
'test1' => { 'score' => '9.18' }, 'test2' => { 'score' => '2.84' },
'190' => { 'test3' => { 'score' => '18.50' }, 'test4' => { 'score' => '14.88' }
'test1'=> {'score' => '13.28' }, 'test2' => { 'score' => '-47.56' } } }
Sorting is to be done based on descending score value.
I have tried out the below code but it kind-of sorts based on the main-key. I need output as shown in the expected hash structure.
my @sort_by_rank;
for my $key1 (keys %rankBased) {
for my $key2 (keys %{$rankBased{$key1}}) {
@sort_by_rank = sort{ $rankBased{$b}{$key2}{score} <=> $rankBased{$a}{$key2}{score}
} keys %rankBased;
}
}
Here %rankBased is the hash.
Please help.
You can't sort a hash, but you can sort the list of a hash's keys.
for my $student_id (keys %tests_by_student_id) {
my $tests = $tests_by_student_id{$student_id};
my @sorted_test_ids =
sort { $tests->{$b}{score} <=> $tests->{$a}{score} }
keys(%$tests);
# Do something with the student's sorted tests here.
}
(Meaningless %rankBased
renamed to %tests_by_student_id
.)
The above is great is you want to do something with each student. But if you actually want to "sort the hash", you'll need to switch to a different structure.
for my $student_id (keys %tests_by_student_id) {
# This next line is the same as
# my $tests = $tests_by_student_id{$student_id};
# except changing $tests also changes
# $tests_by_student_id{$student_id}.
for my $tests ($tests_by_student_id{$student_id}) {
$tests = [
sort { $b->{score} <=> $a->{score} }
map { { id => $_, %{ $tests->{$_} } } }
keys(%$tests)
];
}
}
This produces
$VAR1 = {
'191' => [ { id => 'test3', score => 15.62 },
{ id => 'test4', score => 11.84 },
{ id => 'test1', score => 9.18 },
{ id => 'test2', score => 2.84 } ],
'190' => [ { id => 'test3', score => 18.50 },
{ id => 'test4', score => 14.88 },
{ id => 'test1', score => 13.28 },
{ id => 'test2', score => -47.56 } ],
};