=head3 Version Strings
X<version string> X<vstring> X<v-string>
-B<Note:> Version Strings (v-strings) have been deprecated. They will
-be removed in some future release after Perl 5.8.1. The marginal
-benefits of v-strings were greatly outweighed by the potential for
-Surprise and Confusion.
-
A literal of the form C<v1.20.300.4000> is parsed as a string composed
of characters with the specified ordinals. This form, known as
v-strings, provides an alternative, more readable way to construct
print 102.111.111; # same
Such literals are accepted by both C<require> and C<use> for
-doing a version check. The C<$^V> special variable also contains the
-running Perl interpreter's version in this form. See L<perlvar/$^V>.
-Note that using the v-strings for IPv4 addresses is not portable unless
-you also use the inet_aton()/inet_ntoa() routines of the Socket package.
+doing a version check. Note that using the v-strings for IPv4
+addresses is not portable unless you also use the
+inet_aton()/inet_ntoa() routines of the Socket package.
Note that since Perl 5.8.1 the single-number v-strings (like C<v65>)
are not v-strings before the C<< => >> operator (which is usually used
may be used to indicate the logical end of the script before the actual
end of file. Any following text is ignored.
-Text after __DATA__ but may be read via the filehandle C<PACKNAME::DATA>,
+Text after __DATA__ may be read via the filehandle C<PACKNAME::DATA>,
where C<PACKNAME> is the package that was current when the __DATA__
token was encountered. The filehandle is left open pointing to the
contents after __DATA__. It is the program's responsibility to
"barewords". As with filehandles and labels, a bareword that consists
entirely of lowercase letters risks conflict with future reserved
words, and if you use the C<use warnings> pragma or the B<-w> switch,
-Perl will warn you about any
-such words. Some people may wish to outlaw barewords entirely. If you
+Perl will warn you about any such words. Perl limits barewords (like
+identifiers) to about 250 characters. Future versions of Perl are likely
+to eliminate these arbitrary limitations.
+
+Some people may wish to outlaw barewords entirely. If you
say
use strict 'subs';
It is often more readable to use the C<< => >> operator between key/value
pairs. The C<< => >> operator is mostly just a more visually distinctive
synonym for a comma, but it also arranges for its left-hand operand to be
-interpreted as a string -- if it's a bareword that would be a legal simple
-identifier (C<< => >> doesn't quote compound identifiers, that contain
-double colons). This makes it nice for initializing hashes:
+interpreted as a string if it's a bareword that would be a legal simple
+identifier. C<< => >> doesn't quote compound identifiers, that contain
+double colons. This makes it nice for initializing hashes:
%map = (
red => 0x00f,
square brackets. For example:
@myarray = (5, 50, 500, 5000);
- print "Element Number 2 is", $myarray[2], "\n";
+ print "The Third Element is", $myarray[2], "\n";
The array indices start with 0. A negative subscript retrieves its
value from the end. In our example, C<$myarray[-1]> would have been
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