Yes, the question should be reworded to "Which of the following is an object constructor in Perl?" and the answer is "depends on the module". Though "bless" is almost a better answer than "new" as are "TIESCALAR", etc.

Though the tradition of using "new" is so strong that I can understand that answer. I can't, at the moment, think of a single object module that doesn't provide "new" as a constructor.

Though the tradition of using "new" is so strong that I can understand that answer. I can't, at the moment, think of a single object module that doesn't provide "new" as a constructor.

DBI, for one. Uses connect.

-- Randal L. Schwartz, Perl hacker

There's a difference between a "constructor" method, which gives you back a newly created (and possibly initialized) instance of a named class, and a "factory" method, which you invoke on an instance of one class to get back a newly created (and possibly initialized) instance of a different class.

The difference is in whether or not you need to know the class name. Factory methods "hide" that need, which is a Very Good Thing when you're building class hierarchies that other might extend.

DBI's prepare is a factory method, not a constructor.

Another example of constructors not names "new" would be in the TK module. All constructors in this module are named after the widgets that they create.

DBI also uses a "prepare" constructor.

Cheers,
Ovid

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The short answer is that new returns a newly blessed object by convention. You could as easily write something that doesn't always return a new object. Consider:

package Singleton;
...
my $singleton = undef;

sub new {
    my $pkg = shift;
    $singleton ||= bless {}, $pkg;
}
...
my $frob = new Singleton();
[download]

That word new isn't special. You could have written a construct this way, too...

--
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