perl的排序和比較

來源:互聯網
上載者:User

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

 

perl 比較操作符列表: 

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

 

<=> 和cmp的詳細解釋: 

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...)(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! 

相關文章

聯繫我們

該頁面正文內容均來源於網絡整理,並不代表阿里雲官方的觀點,該頁面所提到的產品和服務也與阿里云無關,如果該頁面內容對您造成了困擾,歡迎寫郵件給我們,收到郵件我們將在5個工作日內處理。

如果您發現本社區中有涉嫌抄襲的內容,歡迎發送郵件至: info-contact@alibabacloud.com 進行舉報並提供相關證據,工作人員會在 5 個工作天內聯絡您,一經查實,本站將立刻刪除涉嫌侵權內容。

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.