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authorDan Book <grinnz@gmail.com>2016-04-15 03:23:10 -0400
committerDan Book <grinnz@gmail.com>2016-04-15 03:23:10 -0400
commitf6b16c69bb7631be65b60f866928d06dc6453e96 (patch)
tree487769302e1977dbbf39201081a3d2d7f2803444 /perl.html.markdown
parent8c9bcf460f763987515f692e82b1c1aecc3f9f86 (diff)
[perl/en] Fix line formatting and use $x instead of $a
Diffstat (limited to 'perl.html.markdown')
-rw-r--r--perl.html.markdown85
1 files changed, 45 insertions, 40 deletions
diff --git a/perl.html.markdown b/perl.html.markdown
index 61e8cd0e..3cbd2801 100644
--- a/perl.html.markdown
+++ b/perl.html.markdown
@@ -21,9 +21,9 @@ use strict;
use warnings;
# All perl scripts and modules should include these lines. Strict causes
-# compilation to fail in cases like misspelled variable names, and warnings
-# will print warning messages in case of common pitfalls like concatenating
-# to an undefined value.
+# compilation to fail in cases like misspelled variable names, and
+# warnings will print warning messages in case of common pitfalls like
+# concatenating to an undefined value.
#### Perl variable types
@@ -47,8 +47,8 @@ my @animals = ("camel", "llama", "owl");
my @numbers = (23, 42, 69);
my @mixed = ("camel", 42, 1.23);
-# Array elements are accessed using square brackets, with a $ to indicate
-# one value will be returned.
+# Array elements are accessed using square brackets, with a $ to
+# indicate one value will be returned.
my $second = $animals[1];
## Hashes
@@ -56,7 +56,8 @@ my $second = $animals[1];
my %fruit_color = ("apple", "red", "banana", "yellow");
-# You can use whitespace and the "=>" operator to lay them out more nicely:
+# You can use whitespace and the "=>" operator to lay them out more
+# nicely:
my %fruit_color = (
apple => "red",
@@ -71,8 +72,8 @@ my $color = $fruit_color{apple};
#### References
-# More complex data types can be constructed using references, which allow
-# you to build arrays and hashes within arrays and hashes.
+# More complex data types can be constructed using references, which
+# allow you to build arrays and hashes within arrays and hashes.
my $array_ref = \@array;
my $hash_ref = \%hash;
@@ -88,13 +89,14 @@ my $colors = {apple => "red", banana => "yellow"};
my @fruits_array = @$fruits;
my %colors_hash = %$colors;
-# As a shortcut, the arrow operator can be used to dereference and access a
-# single value.
+# As a shortcut, the arrow operator can be used to dereference and
+# access a single value.
my $first = $array_ref->[0];
my $value = $hash_ref->{banana};
-# See perlreftut and perlref for more in-depth documentation on references.
+# See perlreftut and perlref for more in-depth documentation on
+# references.
#### Conditional and looping constructs
@@ -150,18 +152,18 @@ print $hash_ref->{$_} for keys %$hash_ref;
#### Regular expressions
-# Perl's regular expression support is both broad and deep, and is the subject
-# of lengthy documentation in perlrequick, perlretut, and elsewhere.
-# However, in short:
+# Perl's regular expression support is both broad and deep, and is the
+# subject of lengthy documentation in perlrequick, perlretut, and
+# elsewhere. However, in short:
# Simple matching
if (/foo/) { ... } # true if $_ contains "foo"
-if ($a =~ /foo/) { ... } # true if $a contains "foo"
+if ($x =~ /foo/) { ... } # true if $x contains "foo"
# Simple substitution
-$a =~ s/foo/bar/; # replaces foo with bar in $a
-$a =~ s/foo/bar/g; # replaces ALL INSTANCES of foo with bar in $a
+$x =~ s/foo/bar/; # replaces foo with bar in $x
+$x =~ s/foo/bar/g; # replaces ALL INSTANCES of foo with bar in $x
#### Files and I/O
@@ -172,9 +174,10 @@ open(my $in, "<", "input.txt") or die "Can't open input.txt: $!";
open(my $out, ">", "output.txt") or die "Can't open output.txt: $!";
open(my $log, ">>", "my.log") or die "Can't open my.log: $!";
-# You can read from an open filehandle using the "<>" operator. In scalar
-# context it reads a single line from the filehandle, and in list context it
-# reads the whole file in, assigning each line to an element of the list:
+# You can read from an open filehandle using the "<>" operator. In
+# scalar context it reads a single line from the filehandle, and in list
+# context it reads the whole file in, assigning each line to an element
+# of the list:
my $line = <$in>;
my @lines = <$in>;
@@ -197,9 +200,9 @@ logger("We have a logger subroutine!");
#### Modules
-# A module is a set of Perl code, usually subroutines, which can be used in
-# other Perl code. It is usually stored in a file with the extension .pm so
-# that Perl can find it.
+# A module is a set of Perl code, usually subroutines, which can be used
+# in other Perl code. It is usually stored in a file with the extension
+# .pm so that Perl can find it.
package MyModule;
use strict;
@@ -219,24 +222,25 @@ sub trim {
use MyModule;
MyModule::trim($string);
-# The Exporter module can help with making subroutines exportable, so they
-# can be used like this:
+# The Exporter module can help with making subroutines exportable, so
+# they can be used like this:
use MyModule 'trim';
trim($string);
-# Many Perl modules can be downloaded from CPAN (http://www.cpan.org/) and
-# provide a range of features to help you avoid reinventing the wheel. A
-# number of popular modules like Exporter are included with the Perl
-# distribution itself. See perlmod for more details on modules in Perl.
+# Many Perl modules can be downloaded from CPAN (http://www.cpan.org/)
+# and provide a range of features to help you avoid reinventing the
+# wheel. A number of popular modules like Exporter are included with
+# the Perl distribution itself. See perlmod for more details on modules
+# in Perl.
#### Objects
-# Objects in Perl are just references that know which class (package) they
-# belong to, so that methods (subroutines) called on it can be found there.
-# The bless function is used in constructors (usually new) to set this up.
-# However, you never need to call it yourself if you use a module like Moose
-# or Moo (see below).
+# Objects in Perl are just references that know which class (package)
+# they belong to, so that methods (subroutines) called on it can be
+# found there. The bless function is used in constructors (usually new)
+# to set this up. However, you never need to call it yourself if you use
+# a module like Moose or Moo (see below).
package MyCounter;
use strict;
@@ -260,7 +264,8 @@ sub increment {
1;
-# Methods can be called on a class or object instance with the arrow operator.
+# Methods can be called on a class or object instance with the arrow
+# operator.
use MyCounter;
my $counter = MyCounter->new;
@@ -268,9 +273,9 @@ print $counter->count, "\n"; # 0
$counter->increment;
print $counter->count, "\n"; # 1
-# The modules Moose and Moo from CPAN can help you set up your object classes.
-# They provide a constructor and simple syntax for declaring attributes. This
-# class can be used equivalently to the one above.
+# The modules Moose and Moo from CPAN can help you set up your object
+# classes. They provide a constructor and simple syntax for declaring
+# attributes. This class can be used equivalently to the one above.
package MyCounter;
use Moo; # imports strict and warnings
@@ -284,8 +289,8 @@ sub increment {
1;
-# Object-oriented programming is covered more thoroughly in perlootut, and its
-# low-level implementation in Perl is covered in perlobj.
+# Object-oriented programming is covered more thoroughly in perlootut,
+# and its low-level implementation in Perl is covered in perlobj.
```
#### FAQ