Question

我有这个结构：

      '$self' => {

         'stepTimePercentage' =>{

                'id12' => {
                     'percentage' => '1.00'
                   },
                 'id15' => {
                     'percentage' => '30.00'
                   },
                 'id4' => {
                     'percentage' => '20.00'
                   },
                 'id9' => {
                     'percentage' => '15.00'
                   },
               }

           }

我想按照＆＃39;百分比＆＃39;的值对此结构进行排序。我尝试了以下内容，但我得到了：＆＃34;在数字比较中使用未初始化的值（＆lt; =＆gt;）＆＃34;。

foreach my $key (sort{ $self->{stepTimePercentage}->{percentage}{$b} <=> $self->{stepTimePercentage}->{percentage}{$a} } keys %{$self->{stepTimePercentage}}) {
    print "$key - $self->{stepTimePercentage}->{$key}->{percentage} % \n";
}

然后我尝试了这个（我得到了＆＃34;全局符号＆＃34; $ key＆＃34;需要明确的包名＆＃34;）：

foreach my $key (sort{ $self->{stepTimePercentage}{key}{$b} <=> $self->{stepTimePercentage}{$key}{$a}} keys %{$self->{stepTimePercentage}}) {
    print ("$key - $self->{stepTimePercentage}->{$key}->{percentage} % \n");
}

Answer 1

你几乎就在那里。你要排序的关键是三级哈希的第二级，所以你想要：

foreach my $key (sort { 
    $self->{stepTimePercentage}{$b}{percentage}
       <=> 
    $self->{stepTimePercentage}{$a}{percentage} 
} keys %{$self->{stepTimePercentage}}) {

    print "$key - $self->{stepTimePercentage}->{$key}->{percentage} % \n";

}

Perl按类值排序类似哈希的Perl哈希值

1 个答案: