perl的排序和比较

发布时间：2020-12-16 00:16:09 所属栏目：大数据来源：网络整理

导读：来自：http://www.perlfect.com/articles/sorting.shtml ? perl 比较操作符列表：? Numbers Strings lt gt = le = ge == eq = cmp != ne ? = 和cmp的详细解释： ? Relation of $a and $b Value Returned by $a = $a greater than $b 1 $a equal to $b 0 $a l

来自：http://www.perlfect.com/articles/sorting.shtml

perl 比较操作符列表：?

Numbers	Strings
<	lt
>	gt
<=	le
>=	ge
==	eq
<=>	cmp
!=	ne

<=> 和cmp的详细解释：?

Relation of $a and $b	Value Returned by $a <=>
$a greater than $b	1
$a equal to $b	0
$a less than $b	-1

如果你有未排序的 @not_sorted，想得到排序的@sorted：??

@sorted = sort { $a <=> $b } @not_sorted # numerical sort or @sorted = sort { $a cmp $b } @not_sorted # ASCII-betical sort or better @sorted = sort { lc($a) cmp lc($b) } @not_sorted # alphabetical sort

Get a list of hash keys sorted by value.

@sorted = sort { $hash{$a} cmp $hash{$b} } keys %hash;

Get a reverse sort of a list.

@sorted = sort { $b cmp $a } @list; Which can also be done with @sorted = reverse sort { $a cmp $b } @list;

Get an alphabetical sort of words,but make 'aardvark' always come last.

(Now,why you would want to do that is another question...)

@sorted = sort { if ($a eq 'aardvark') { return 1; } elsif ($b eq 'aardvark') { return -1; } else { return $a cmp $b; } } @words;

完！?

（编辑：李大同）

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