Different kinds of Perl subroutines

[ranaaich]

Hello All,

I'm a newbie in the Perl. I'm encountering a bit of difficulty understanding various methodology in subroutine calls. Can any one describe the arguments that are getting passed?

Pattern 1: (most common)

sub mysub{
}

Comments: Understood
-------------------------------------
Pattern 2:

sub mysub($)
{
my ($var1, $var2) = @;
.
.
}

Comments : Couldn't understand ($) in the passing argument
---------------------------------------
Pattern 3:

sub mysub(;$)
{
my ($var1, $var2) = @;
.
.
}
Comments : Couldn't understand mysub(;$)
----------------------------------------
Pattern 4:

sub mysub($;$)
{

}
Comments : Couldn't understand mysub($;$)
------------------------------------------
Pattern 5:

sub mysqub($$$$)
{
}

Comments : Couldn't understand mysub($$$$)
-------------------------------------------


Thanking all in advance.

 

[KevinADC]

all but the first example are what are called prototypes in perl. Instead of trying to explain the differences maybe this will help you:

http://www.perl.com/doc/manual/html/pod/perlsub.html

(scroll down to the Protypes section).

Personally, I have never found a good use for prototypes and see little reason to use them. But maybe I am not experienced enough to really understand what their purpose/value is.

 

[icrf]

I'm going to have to second that sentiment. I've played with them a little, but have never felt I needed them.

- Andrew
Text::Highlight - A language-neutral syntax highlighting module in Perl
also on SourceForge including demo