How to sort Array with hashref Elements and custom search function (solved) (Allgemeines zu Perl)

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How to sort Array with hashref Elements and custom search function [solved]

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+6 replies
guest Frank Schuster

2011-04-14 17:58
Hi.

I want to sort the hasref elements of the array @t in the way that the value from the key 'b' in each anonyme hash should be considered in the sorting process. The result shoud be an array with following order:
( {'b','1','w','10'},{'b','2','w','40'},{'b','3','w','30'}).
Code: (dl )

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

@t = ( {'b','1','w','10'},{'b','3','w','30'},{'b','2','w','40'}); foreach $f1 (@t){ foreach $f2 (keys %$f1){ print $$f1{$f2},"\n"; } } @bb = sort func @t; sub func{ print ${$a}{'b'}," ",${$a}{'w'}," :"; print ${$b}{'b'}," ",${$b}{'w'}," \n"; print "xxx",(${$a}{'b'} lt ${$b}{'b'}),"xxx"; print "\n================\n"; return ${$a}{'b'} lt ${$b}{'b'}; } foreach $f1 (@bb){ foreach $f2 (keys %$f1){ print $$f1{$f2},"\n"; } }
The curios result output of my checking statements is the following:
Code: (dl )

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

10 1 30 3 40 2 1 10 :3 30 xxx1xxx ================ 3 30 :2 40 xxxxxx ================ 2 40 :1 10 xxxxxx ================ 30 3 10 1 40 2
Why there is just one output of the comparing process ( 1 surrounded by xxx)?

Can anybody enlighten me?

Regards.

mcfaq
Last edited: 2011-04-14 18:12:09 +0200 (CEST)
- +3 replies
- rosti
  
  2011-04-14 18:37
  User since
  2011-03-19
  3463 articles
  BenutzerIn
  Quote
  Can anybody enlighten me?
  
  Later?
  
  Please take a little look at my Solution
  
  Code (perl): (dl )
  
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
  
  use strict; use warnings; use Data::Dump qw(dump); #my @t = ( {'b','1','w','10'},{'b','3','w','30'},{'b','2','w','40'}); # at first, making hash readable as such my @t = ( {'b' => '1','w' => '10'},{'b' => '3','w' =>'30'},{'b' => '2','w' => '40'}); # consider issue: the value in key 'b' is numeric, use spaceship '<=>' for compare # transform by Randal Schwartz @t = map{$_->[0]} sort{$a->[1] <=> $b->[1]} map{ [$_, $_->{b}] }@t; print dump \@t;
  - +2 replies
  - guest wer
    
    2011-04-14 19:42
    
    Schwartzsche Transformation macht nur bei Scalaren Sinn, wenn alles schon gesplittet ist, ist das doch unnötig.
    
    $a->[1] <=> $b->[1] vs. $a->{b} <=> $b->{b}
    Last edited: 2011-04-14 19:48:47 +0200 (CEST)
    - rosti
      
      2011-04-15 08:03
      
      User since
      2011-03-19
      3463 articles
      BenutzerIn
      
      Guest wer
      Schwartzsche Transformation macht nur bei Scalaren Sinn, wenn alles schon gesplittet ist, ist das doch unnötig.
      
      $a->[1] <=> $b->[1] vs. $a->{b} <=> $b->{b}
      
      Ich habs in dem Moment gesehen, als ich Zeile 15 schrieb ;)
      
      Viele Grüße,
      Rolf
- +2 replies
- topeg
  
  2011-04-14 18:50
  User since
  2006-07-10
  2611 articles
  BenutzerIn
  lt returns true or false. If you want to do a sort you need three values if one value is smaller, equal or bigger. For strings use cmp for numbers <=>.
  
  Example:
  
  Code (perl): (dl )
  
  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
  
  @t = ( {b=>1,w=>10}, {b=>3,w=>30}, {b=>2,w=>40}, {b=>7,w=>60}, {b=>4,w=>70}, {b=>6,w=>90}, {b=>5,w=>100}); print "## RAW #####################\n"; pout(@t); @bb = sort func @t; sub func{ return $a->{b} <=> $b->{b}; } print "## SORTED ##################\n"; pout(@bb); sub pout { foreach $f1 (@_){ foreach $f2 (sort keys %$f1){ print "$f2 $f1->{$f2}\n"; } print "------\n"; } }
  
  ps. Your name looks German. This is a forum for German natives, so if possible please use German.
  - guest Frank Schuster
    
    2011-04-14 22:36
    
    Hi topeg.
    
    That was the mistake. lt or < give only 2 booleans back. I don't considered the requirements.
    
    Thank you so much.
    
    And by the way:
    I forgetted that this is an german forum.
    
    Also das nächste mal gerne auf deutsch. Kommt mir entgegen.
    
    Gruß und vielen Dank.
    Last edited: 2011-04-14 22:39:03 +0200 (CEST)

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