Sort by string length

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

Hi Monks! I have a question on sorting. Say I have the following

@elements = ("hohoho" , "work" , "gates" , "ragarnok" , ".");
[download]

i want to sort the list in the elements from the longest string length to the smallest length. is there any fast/smart way of doing it? I been converting this data into a hash and created a key based on length of the elements and sorting that ie $HASH{"6"}{"hohoho"} = 1;

20040904 Edit by castaway: Changed title from 'Sort Question'

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Re: Sort by string length by kesterkester (Hermit) on Sep 03, 2004 at 21:59 UTC
You can give the sort function a custom sorting subroutine, using the special variables $a and $b. E.g.: `@sorted = sort { length $a <=> length $b } @elements` See also perldoc -q sort	[reply] [d/l]
Re^2: Sort by string length by EchoAngel (Pilgrim) on Sep 03, 2004 at 22:06 UTC
wow......that just blew my mind!	[reply]
Re: Sort by string length by Enlil (Parson) on Sep 03, 2004 at 21:59 UTC
`my @sorted_by_length = sort { length($a) <=> length($b) } @elements;` [download] or if you feel so inclined to do a schwartzian type transform (used when an expensive function is used to evaluate order): `my @sorted_by_length = map { $_->[0] } sort { $a->[1] <=> $b->[1] } map { [ $_, length($_) ] } @elements` [download] HTH -enlil	[reply] [d/l] [select]
Re: Sort by string length by bobf (Monsignor) on Sep 03, 2004 at 22:03 UTC
You can create a custom sort routine by providing a sub of your own. See sort. `@sorted = sort { length($a) <=> length($b) } @elements;` [download] HTH Update: I see I don't type quite as quickly as kesterkester or Enlil... see Re: Sort by string length.	[reply] [d/l]
Re: Sort by string length by Anonymous Monk on Sep 03, 2004 at 23:38 UTC
If your array is small, it doesn't matter how you sort. For large arrays, a GRT is fastest. For instance: `@elements = @elements [map +(unpack $format, $_) [-1], sort map pack ( +$format, length $elements [$_], $_), 0 .. $#elements];` [download] And a GRT is far less memory hungry than an ST.	[reply] [d/l]