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### Re^5: sort hash of arrays of arrays

by BrowserUk (Pope)
 on Oct 31, 2012 at 16:05 UTC ( #1001697=note: print w/replies, xml ) Need Help??

in reply to Re^4: sort hash of arrays of arrays
in thread sort hash of arrays of arrays

Then you need to do one sort for each key in the hash like this:

```@{ \$hash{\$_} } = sort{ \$b->[1] <=> \$a->[1] } @{ \$hash{\$_} } for keys %
+hash;;

pp \%hash;;
{
1 => [[26, 27, 28], [16, 17, 18], [6, 7, 8], [1, 2, 3]],
2 => [[27, 28, 29], [17, 18, 19], [7, 8, 9], [2, 3, 4]],
3 => [[28, 29, 30], [18, 19, 20], [8, 9, 10], [3, 4, 5]],
4 => [[29, 30, 31], [19, 20, 21], [9, 10, 11], [4, 5, 6]],
}

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Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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In the absence of evidence, opinion is indistinguishable from prejudice.

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Re^6: sort hash of arrays of arrays
by maladav (Initiate) on Oct 31, 2012 at 16:31 UTC

It's awesome, thank you!
How does it work? Specifically, why does it need the for keys %hash part? How could I sort on the innermost elements (e.g. [26, 27, 28] to get [28, 27, 26]) using the same method?
Thanks very much.

How does it work? Specifically, why does it need the "for keys %hash" part?

Because, as I said, you need to do one sort for each key.

(I don't know how better to explain it than that. )

How could I sort on the innermost elements (e.g. [26, 27, 28] to get [28, 27, 26]) using the same method?

Now you need to do one sort for each sub array, for each key, so you need nested loops:

```for my \$key ( keys %hash ) {
for my \$aref ( @{ \$hash{ \$key } } ) {
@{ \$aref } = sort { \$b <=> \$a } @{ \$aref };
}
}
;;

pp \%hash;;
{
1 => [[28, 27, 26], [18, 17, 16], [8, 7, 6], [3, 2, 1]],
2 => [[29, 28, 27], [19, 18, 17], [9, 8, 7], [4, 3, 2]],
3 => [[30, 29, 28], [20, 19, 18], [10, 9, 8], [5, 4, 3]],
4 => [[31, 30, 29], [21, 20, 19], [11, 10, 9], [6, 5, 4]],
}

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.

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