Accessing the package variables by fully qualified name

vinoth.ree has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks

I go through some of the projects, there they used the variables of the package with fully qualified name, even though that package has been imported into the current package.

lets say,

 use package_name;<br>
$package_name::main::variablename=10;
[download]

It will be useful in case of if I have the same variable name in the current package which I included this package, Any other advantage is there? Is it the safe mode of accessing the package variables ?

Update :

Title Updated

Comment on Accessing the package variables by fully qualified name Download Code

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Re: Accessing the package variables by fully qualified name by cdarke (Prior) on Jul 30, 2009 at 13:33 UTC
Any other advantage is there? Is it the safe mode of accessing the package variables ? Since the variables have been exported there is no need to use the fully qualified name. The upside of using the fully qualified name is that you can see where the variable originated, the downside is that it is confusing if an unqualified name is used as well, or by accident. It is an argument against exporting variables - better for the module to provide accessor subroutines IMHO.	[reply]
Re^2: Accessing the package variables by fully qualified name by Utilitarian (Vicar) on Jul 30, 2009 at 13:42 UTC
cdarke's humble opinion is correct, the package variables should stay where they are and be accessed through getters and setters, if these are available, use them, if not, well be careful. `$instance_of_package->set_named_variable("new_value");` is more readable I believe and for "class" variables `Package::Name->set_class_variable("new Global");` is more legible to me than direct assignment, provided the accessors are half-way sensibly named.	[reply] [d/l] [select]
Re: Accessing the package variables by filly qualified name by mzedeler (Pilgrim) on Jul 30, 2009 at 12:51 UTC
Importing a package with `use` doesn't automatically export all package variables (and subs) to your namespace, so they may be accessing the variable using fully qualified names because it is the only way to access that particular variable.	[reply] [d/l]
Re^2: Accessing the package variables by filly qualified name by vinoth.ree (Monsignor) on Jul 30, 2009 at 13:00 UTC
Yes, you are right thanks for an idea, but they used fully qualified name for when they change the value of that variable.	[reply]
Re^3: Accessing the package variables by filly qualified name by mzedeler (Pilgrim) on Jul 30, 2009 at 13:08 UTC
...sorry I don't understand. Is it that the variable has been exported, but when its being changed, its addressed using its fully qualified name?	[reply]
Re^4: Accessing the package variables by filly qualified name by vinoth.ree (Monsignor) on Jul 30, 2009 at 13:19 UTC
Re^5: Accessing the package variables by filly qualified name by mzedeler (Pilgrim) on Jul 30, 2009 at 13:30 UTC
Re: Accessing the package variables by fully qualified name by Anonymous Monk on Jul 31, 2009 at 02:35 UTC
Why don't you just ask them to explain their reasons?	[reply]