This turns sub1 and sub2 into closures (see 'What's a closure?'). While it is not always necessary to use BEGIN blocks, without them (i.e. normal blocks), declaration order becomes significant.
Update: A trick I use occasionally is to declare a set of lexical variables in a BEGIN block along with access functions. Within the program, only the access functions are visible.
BEGIN {
my ($var1, $var2, $var3);
my @array1;
my %hash1;
sub var1 { $var1 = $_[0] if @_; $var1 }
sub var2 { $var2 = $_[0] if @_; $var2 }
sub var3 { $var3 = $_[0] if @_; $var3 }
# for arrays and hashes, call in scalar context and
# dereference to manipulate contents
sub array1 { wantarray ? @array1 : \@array1 }
sub hash1 { wantarray ? %hash1 : \%hash1 }
}
Of course, rather than hand code access functions for every variable, I typically define a hash containing my variables as keys, and an AUTOLOAD to define access functions dynamically on first use.
dmm
If you GIVE a man a fish you feed him for a day
But, TEACH him to fish and you feed him for a lifetime
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|