Split string into hash

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

Hi Monks,

I tried the string convert to hash in the following format.

$string="1:one;2:two;3:three";
%hash=(1=>"one", 2=>"two", 4=>"three");

I wrote the code below, but not getting the above hash. Kindly let me know what is the issue, and solution.

use Data::Dumper;

%hash =     (split /\:/,  (split /;/ $string));
print Dumper \%hash;
[download]

now getting output is:

$VAR1 = {
          '3' => undef
        };
[download]

Comment on Split string into hash Select or Download Code

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Re: Split string into hash by davido (Cardinal) on Feb 10, 2011 at 06:30 UTC
You don't have to split twice. Perl is smart enough to know how to load a flat list into a hash. `use strict; use warnings; use Data::Dumper; my $string = "1:one;2:two;3:three"; my %hash = split /[;:]/, $string; print Dumper \%hash;` [download] The output is: `$VAR1 = { '1' => 'one', '3' => 'three', '2' => 'two' };` [download] No guarantees as to the order, as hashes aren't sorted. Dave	[reply] [d/l] [select]
Re: Split string into hash by andreas1234567 (Vicar) on Feb 10, 2011 at 06:19 UTC
Your code contains syntax errors, and had you used warnings you would have gotten some hints on what is wrong. I would do something like this: `$ perl use strict; use warnings; use Data::Dumper; my $string="1:one;2:two;3:three"; my %hash; my @list1 = split /;/, $string; foreach my $item(@list1) { my ($i,$j)= split(/:/, $item); $hash{$i} = $j; } print Dumper \%hash; __END__ $VAR1 = { '1' => 'one', '3' => 'three', '2' => 'two' }; $` [download] -- No matter how great and destructive your problems may seem now, remember, you've probably only seen the tip of them. [1]	[reply] [d/l]
Re: Split string into hash by Anonymous Monk on Feb 10, 2011 at 06:20 UTC
`%hash = map{split /\:/, $_}(split /;/, $string);` [download]	[reply] [d/l]
Re: Split string into hash by chrestomanci (Priest) on Feb 10, 2011 at 11:11 UTC
We had almost the same homework question yesterday. This one at least shows some effort to solve the problem, but I do wonder where the question comes from.	[reply]
Re: Split string into hash by sundialsvc4 (Abbot) on Feb 10, 2011 at 15:00 UTC
Obviously some University or trade-school out there is in its fifth week of classes ... and full of lazy students. (I have been a college professor, so I can say that.) Nevertheless, I would caution that when dealing with “real” data, it isn’t enough to simply write code that works perfectly when given correct data, but that behaves unpredictably at all other times. `#define SOAPBOX` Data will contain errors and inconsistencies, and the only player that can detect them is: the computer itself. If the computer detects that it is in a situation where it cannot meaningfully continue, it should not allow itself to continue. Only the computer can make that determination. If the software does not aggressively test its data, it is usually impossible to determine whether the problem is with the software or with the data or both. Per contra, if it does do so, it becomes impossible to assert that the input data does not contain the issues that are being tested for ... a very important thing to be able to say in a real-world production setting, where hundred-megabyte input files are common. `#undef SOAPBOX`	[reply]