get all nodes from multi level hash in perl

Question

I want all nodes of each key sorted by key in hash ref or array or something like so that I can iterate that according to my need since I have to display each key with its all children. following is my data structure:

 $hash1 = {
          '3' => {                  

                   'title' => 'Parent-3', 
                    'parentid' => '-1'               
                 },
          '1' => {

                   'children' => {
                                   '11' => {                                           
                                             'title' => 'child-1',                                            
                                           },
                                   '5' => {

                                            'children' => {
                                                            '8' => {                                                                   
                                                                     'title' => 'first child of child-2',                                                                    
                                                                   },
                                                            '13' => {                                                                     
                                                                      'title' => 'second child of child-2',                                                                    
                                                                    }
                                                          },
                                            'title' => 'child-2',                                          
                                          }
                                 },
                   'title' => 'Parent-1', 
                    'parentid' => '-1'                
                 },
          '2' => {                 
                   'title' => 'Parent-2',  
                    'parentid' => '-1'              
                 },
          '4' => {                 
                   'title' => 'Parent-4',
                   'parentid' => '-1'
                 },
        };

I have used following functions :

sub Options {

    my $hash = shift;
    my $options = '';

    my $iter; $iter = sub {     
        my $hash = shift;
        my $indent = shift || '';
        foreach my $k (sort {$a <=> $b} keys %{$hash}) {            
            my $v = $hash->{$k};                
            if($v->{parentid} eq '-1'){
            $options .= $v->{title} ."-parent\n";           
            }else{
            $options .= $v->{title} . "," ;
            }
            if ($v->{children}){
                 $iter->($v->{children}, $indent . "");             
            }                   
        }
        chop($options);
        $options .= "\n";
    };

    $iter->($hash);     
    return $options;
}

here it returns a string with comma separated but I need some kind of data structure so that I can able to find all children for each key (in the form of hash ref or array) like:

Parent-1 -> [child-1,child-2, first child of child-2, second child of child-2]
Parent-2
Parent-3
Parent-4

any one can help me out? thanks in advance.

could you provide **exact** desired output for above structure? — mpapec, Sep 19 '13 at 07:50
actually hash keys 1,2,3,4 are display order and I want to make a hash ref or array whose key will be title and according to that title I want all children so that I can pass that array or hash ref to my template and compare each title and fetch all children and display them on my page. — ABHISHEK GOYAL, Sep 19 '13 at 07:55
Can you replace `$options` with an array (say `@descendants`), and change the `$options .= xxx` to be `push @descendants, xxx`. Change a couple of other places to use the array rather than the scalar/ That gives you an array of the descendants of each top level item. — AdrianHHH, Sep 19 '13 at 08:33

score 1 · Answer 1 · answered Sep 19 '13 at 09:45

1

If your only goal is to display the hash contents, you should use the Data::Dumper module. It can be used to print data structures of arbitrary complexity with a good format.

answered Sep 19 '13 at 09:45

Joseph R.

785
4
11

+1, there is no need to waste time reinventing wheels. `Data::Dumper`, `Data::Dump` and similar modules are the fastest way to achieve the OP's functionality – Zaid Sep 19 '13 at 14:18

score 0 · Answer 2 · edited May 23 '17 at 11:58

0

You may also find brian d foy's answer on checking key existence useful

The code for with code for walking a data structure and Data::Diver may give you all the help you need.

edited May 23 '17 at 11:58

Community

1
1

answered Sep 19 '13 at 17:28

numeric illustration

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1
6

get all nodes from multi level hash in perl

2 Answers2