hash references

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: hash references by moritz (Cardinal) on Aug 01, 2011 at 11:33 UTC
i gave refrence as you see No, we don't see, because you don't show how that sub is called. Why do you persistently ignore the advise from previous threads to actually read perlreftut and start to learn how references work in Perl? Also I don't see any hash references which you mention in the post title. There's no reason for two separate hashes that hold the same information. Perl 6 - second systems done right	[reply]
Re^2: hash references by Anonymous Monk on Aug 01, 2011 at 11:44 UTC
thanks.i know that when we want put an array for a key we have to reference to that for calling it back.but when i change to following code it is still not working and i have error. `my $m=(${@{$site1{$_}}}[1]-${@{$site2{$_}}}[1]); my $n=(${@{$site1{$_}}}[0]-${@{$site2{$_}}}[0]);` [download] now, `@{$site1{$_}}` is a reference,isnt it?	[reply] [d/l] [select]
Re^3: hash references by jethro (Monsignor) on Aug 01, 2011 at 12:04 UTC
No, `@{$site1{$_}}` is a "normal" array. Hopefully `$site1{$_}` is a reference to an array, otherwise you are in trouble (either you have "use strict" then this will give an error, without it you might get no error but it still won't work as you intent What you probably want is something like `$site1{$_}->[1]`. This will access array index 1 of the array pointed to by `$site{$_}`	[reply] [d/l] [select]
Re^4: hash references by Anonymous Monk on Aug 01, 2011 at 12:19 UTC
Re^5: hash references by jethro (Monsignor) on Aug 01, 2011 at 14:36 UTC
Re^3: hash references by moritz (Cardinal) on Aug 01, 2011 at 11:49 UTC
If `$site{$_}` contains an array reference, you can simply get the first item with `$site{$_}[0]` - no need for all those curlies. Perl 6 - second systems done right	[reply] [d/l] [select]
Re^4: hash references by Anonymous Monk on Aug 01, 2011 at 11:57 UTC
Re^5: hash references by moritz (Cardinal) on Aug 01, 2011 at 12:01 UTC
Re: hash references by JavaFan (Canon) on Aug 01, 2011 at 11:58 UTC
Considering that `%site1` and `%site2` are the same, why not replace the subroutine by a much simpler `sub foo {1/0} # Triggers Illegal division by zero` [download]	[reply] [d/l] [select]
Re^2: hash references by ricDeez (Scribe) on Aug 01, 2011 at 14:22 UTC
Well, it would actually be: `sub foo {0/0}` [download] But I am totally with you on this... there is something badly wrong with how he is unpacking the vars into the subroutine!	[reply] [d/l]
Re^3: hash references by JavaFan (Canon) on Aug 01, 2011 at 14:33 UTC
Unless there's some overloaded constant in effect, there's no difference beteen `0/0` and `1/0`. Or `1238/0`.	[reply] [d/l] [select]