Getting wrong argument value when trying to call a subroutine using PackageName::ModuleName->subroutine("xyz")in perl - perl

Question

When trying to call a subroutine (defined in a user defined module) in other perl file, getting wrong argument value
#moduleName.pm
package PackageName::moduleName;
use strict;
use warnings;
use base 'Exporter';
sub callMe{
my($readArg)=(#_);
print $readArg;
}
#test.pl
use strict;
use warnings;
use FindBin; # locate this script
use lib 'path to parent directory'; # use the parent directory
use PackageName::moduleName;
if( my $temp=PackageName::moduleName->callMe("test")){
print" True : $temp\n";
}
The function prints value of $temp as : PackageName::moduleName
Not able to figure out why.
P.S. I have to maintain same convention while calling the subroutine

Answer 1

You are calling a function as a class method with Foo::Bar->frobnicate(#args). In that case, Perl will do the following things because of the arrow ->:
check what's on the left of the arrow
if it's blessed, find the package (e.g. $q is package CGI)
if it's not blessed, assume it's a package (e.g. Foo::Bar)
within that package namespace, find a sub with the name on the right of the arrow (e.g. frobnicate)
call that sub and pass what's on the left of the arrow as the first argument
Now it looks like this:
Foo::Bar::frobnicate('Foo::Bar', #args);
In frobnicate, you have to deal with that:
sub frobnicate {
my ($class, #args) = #_;
# ...
}
That's typically done in a new, which is the most likely use of a class method.
If you don't want to deal with it, call the sub directly in its namespace, and not with the arrow notation.
my $rv = Foo::Bar::frobnicate(#args);

Answer 2

Because of the way you're calling it via ->.
When you do this, perl passes extra arguments, so you can make a constructor (new).
E.g.
my $thing = Package::Module -> new();
The first argument passed is the class, so you can use that for a bless. See:
perlootut
E.g.
sub new {
my ( $class, #args ) = #_;
my $self = {};
bless ( $self, $class );
}
This also applies when you call an instantiated object:
$thing -> do_something();
It passes a reference to $self as the first argument.
sub do_something {
my ( $self, #args ) = #_;
print "Got args of #args\n";
$self -> {firstarg} = shift ( #args );
}
If you want to do that, try instead:
PackageName::ModuleName::callMe("test");