use Socket # This defines PF_INET and SOCK_STREAM $port = 12345; # The unique port used by the sever to listen requests $server_ip_address = "10.12.12.168"; bind( SOCKET, pack_sockaddr_in($port, inet_aton($server_ip_address))) or die "Can't bind to port $port! \n"; 123456 ...
my @unique; my %seen; foreach my $value (@words) { if (! $seen{$value}) { push @unique, $value; $seen{$value} = 1; } } 这里用普通的foreach循环一个个处理原数组中的值,处理过程中使用了辅助哈希表%seen,因为哈希表的键是唯一的。 开始的时候哈希表是空的,所以当遇到第一个"foo"的...
use strict; use warnings; my @original = qw/foo bar hello world foo bar f00 bar barr/; # = array with input data my %uniques; my @dupes = grep $uniques{$_}++, @original; print "unique: "; print join ', ', keys %uniques; # output unique elements print "\nduplicate: "; pri...
Now that we have the list of values in an array we can usemapon the array. That's how we get the expressionsmap { $_ => 1 } @{$_[0]}. This map returns a list of values. Each odd value would be one of the elements of the original array, and each even value would be the...
如果传入*,返回一个lazy, infinite sequence of randomly chosen elements 匹配、筛选、分类 LIST.flat LIST.flatmap(CODE) #flat之后再map LIST.grep(MATCHER, :RETURN_AS) #相对Perl5增加了:RETURN_AS,可以是:k,:v,:kv,:p LIST.first(MATCHER, :RETURN_AS, :FROM_END) ...
Perl 诊断消息 类别含义 (W)警告(可选) (D)反对(可选) (S)严重警告(必需) (F)致命错误(可捕获) (P)你应该从未见过的内部错误(恐慌性的)(可捕获) (X)非常致命的错误(不可捕获) (A)外来错误消息(不是Perl生成的)
How can I get the unique keys from two hashes? How can I store a multidimensional array in a DBM file? it? How can I make my hash remember the order I put elements into create it? Why does passing a subroutine an undefined element in a hash class/hash or array of hashes or ...
Subroutine arguments created only when they're modified In Perl 5.004, nonexistent array and hash elements used as subroutine parameters are brought into existence only if they are actually assigned to (via @_). perl v5.12.5 Last change: 2012-11-03 2 Perl Programmers Reference Guide PERL5004...
Non-capturing groupings are also useful for removing nuisance elements gathered from a split operation where parentheses are required for some reason: $x = '12aba34ba5'; @num = split /(a|b)+/, $x; # @num = ('12','a','34','a','5') ...
my @array; while (<>) { chomp; push @array, split / /, $_; } my @uniques = uniq( @array ); sub uniq { my %seen; my @unique_elements = grep { !$seen{ lc $_ }++ } @_; return @unique_elements; } say Dumper \@uniques; ...