Re: Classes Are Killing Me

Use the $class you're shifting off in your constructor. That's what bless uses to associate a data structure with a class name.

sub new {
    my $class = shift;
    bless({}, $class);
}
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I use an anonymous hash there so you're not recreating the same object each time -- if you use $Person::list, you'll always get back the same object. That may be what you want, if you know what a Singleton is, but get this part down first and add complexity later. :)

Oh, and in your accessors, shift off $self and use that. Have you read perltootc?

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Re: Re: Classes Are Killing Me by straywalrus (Friar) on May 19, 2002 at 04:57 UTC
I do know what a singleton is, but thanx for that pointer. I got the idea to use the local copy of I had originally just copied the data used in the users junk to the module. but even when i used this constructor: `sub new { my $class = shift; my $self = {}; return bless $self, $class; }` [download] It actually did not work at all. Besides, the second simplest constructor in the perl cookbook was `sub new{ bless({},shift);}` I saw that in the reference they had shifted off of `$self` for every function, but as I said earlier I was just copying the code to local vars and only now realize that I can only have one instance of the class if I do that. Yes I realize how to shift of `$self`, but even when I had all the things that were just descibed, I still could not call the functions like this:`$foo->name("straywalrus");`. Instead I had to call every function with the class name preceding the function name with the C++ scope operators betwixt the two ( I have no idea what the scope "::" operator is called in Perl). Every call was made like it was shown in the test program. Surely there is a way to correct this, even though I shift off `$self` and do as was above described. Thanx straywalrus	[reply] [d/l] [select]
Re: Re: Re: Classes Are Killing Me by chromatic (Archbishop) on May 19, 2002 at 05:17 UTC
The simplest remaining possibility is that $foo is not a person, that your constructor is somehow failing. This could be due to the package not loading. If I were you, I'd enable strictures and warnings and add this line after attempting to create the object: `print "Foo is a ", ref($foo), "!\n";` [download] You shouldn't have to preface method calls with package names, nor do you need to import anything from Person (so you can safely drop the method name list). Oh, and the double colons are package name separators.	[reply] [d/l]