Re: Hash Sorting Problem

Dear List

I need to delete each element after every execution of the foreach loop and
I need to update & sorted the @arr1 after every execution of the foreach
loop. I have tried a lot but not able to do this ............Pls
help...........

Thanks & Regards
Anirban Adhikary

On Mon, Feb 25, 2008 at 1:51 PM, John W. Krahn <krahnj@xxxxxxxxx> wrote:

Anirban Adhikary wrote:
Dear List

Hello,

I have written the following code .............

use Data::Dumper;


%file = (14 => "GGG",
11 => "AAA",
101 => "EEE",
1 => "TTT");


print Dumper \%file;



@arr1 = sort { $file{$b} cmp $file{$a} } keys %file; #the oldest entry
lies
at the top position

print Dumper \@arr1;

foreach $el(@arr1)
{

delete $file{$el};
print "The $el is removed from the sorted list"."\n";
@arr1 = sort { $file{$b} cmp $file{$a} } keys %file; #the oldest entry
lies

perldoc perlsyn
[ SNIP ]
If any part of LIST is an array, "foreach" will get very confused if
you add or remove elements within the loop body, for example with
"splice". So don't do that.


at the top position
print "After sorting the array elements are"."\n";
print Dumper \@arr1;
}


---------------output ------------

$VAR1 = {
'1' => 'TTT',
'11' => 'AAA',
'101' => 'EEE',
'14' => 'GGG'
};
$VAR1 = [
'1',
'14',
'101',
'11'
];
The 1 is removed from the sorted list
After sorting the array elements are
$VAR1 = [
'14',
'101',
'11'
];
The 101 is removed from the sorted list
After sorting the array elements are
$VAR1 = [
'14',
'11'
];

In the last output I think the list is not sorted properly. How can I
solve
this problem.

It is sorted properly, it's just that you are modifying the array @arr1
inside a foreach loop that iterates over that same array and you
shouldn't do that.



John
--
Perl isn't a toolbox, but a small machine shop where you
can special-order certain sorts of tools at low cost and
in short order. -- Larry Wall


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