如何在Perl中按二级哈希值排序？

Question

my $hash_ref = {
    one   => { val => 1, name => 'one'  },
    three => { val => 3, name => 'three'},
    two   => { val => 2, name => 'two'  },
};

我想排序$hash_ref一个foreach将它们命令

$hash_ref->{$key}->{'val'}

one
two
three

有什么建议？

Answer 1

@sorted_list 是对已排序的哈希元素的引用数组:

 @sorted_list = sort { $a->{'val'} <=> $b->{'val'} } values %{$unsorted_hash_ref};

您可以像这样使用它:

#!/usr/bin/perl

my $hash_ref = {
    one   => { val => 1, name => 'one' },
    three => { val => 3, name => 'three' },
    two   => { val => 2, name => 'two' },
};

foreach $elem ( sort { $a->{'val'} <=> $b->{'val'} } values %{$hash_ref} ) {
    print "$elem->{'val'} : $elem->{'name'}\n";
}

输出:

1 : one
2 : two
3 : three