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...
A namespace is a named collection of unique variable names (also called a symbol table). Namespaces prevent variable name collisions between packages. Packages enable the construction of modules which, when used, won't clobber variables and functions outside of the modules's own namespace. The ...
my @unique = uniq @duplicates; say @unique.perl; # prints Array.new(1, 2, 5, 4, 3) my @chars = ; say @chars.perl; # prints Array.new("b", "c", "a", "d", "b", "a", "a", "a", "b") my @singles = uniq @chars; say @singles.perl; # prints Array.new("b", ...
A subroutine receives its paramaters in the@_array. The first element of that array is$_[0]. (Just as the first element of@nameswould be$names[0].) We assume this is a reference to an array and want to de-reference it so we can go over the elements one-by-one. We do that ...
Assigning to an element past the end automatically extends the array: $ARRAY[$NEW_LAST_ELEMENT_INDEX_NUMBER] = $VALUE; Discussion $#ARRAYis the number of the last valid index in@ARRAY. If we assign it a number smaller than its current value, we truncate the array. Truncated elements are...
因此,我们将在Perl中使用三种类型的变量。scalar变量将以美元符号($)开头,它可以存储数字,字符串或引用。array变量将以符号@开头,它将存储有序的标量列表。 最后,Hash变量将以符号%开头,并将用于存储键/值对的集合。 Perl将每个变量类型保存在单独的命名空间中。 因此,您可以在不担心冲突的情况下,为标量变量,数组...
A mapping is a YAML collection defined by unordered key/value pairs with unique keys. By default YAML mappings are loaded into Perl hashes. sequence A sequence is a YAML collection defined by an ordered list of elements. By default YAML sequences are loaded into Perl arrays. ...
How can I get the unique keys from two hashes? How can I store a multidimensional array in a DBM file? How can I make my hash remember the order I put elements into it? Why does passing a subroutine an undefined element in a hash create it? How can I make the Perl equivalent of...
Given an SV , a pattern, and a pointer to an empty AV , matches() evaluates $string =~ $pattern in a list context, and fills in matches with the array elements, returning the number of matches found.Here's a sample program, match.c, that uses all three (long lines have been wrapp...