Ken Perl am Freitag, 17. Februar 2006 02.34:
> what is the difference of :: and -> in this statements?
>
> $authInstance =
> Operation::Auth::getInstance($session,$u->authMethod,$u->userId)
>
> $authInstance =
> Operation::Auth->getInstance($session,$u->authMethod,$u->userId)
The first '::' is part of a package name, the package is
package Operation::Auth
The last '::' (in the first example) denotes a sub in this package and is a
procedure invocation, the sub getting only the passed arguments.
The '->' is a method invocation, and the class name ('Operation::Auth' in this
case) is implicitly passed to getInstance as first argument (as Chas already
said).
The two notations are not interchangeable if the sub definition is for example
sub getInstance {
my ($class, $session, $meth, $uid)[EMAIL PROTECTED];
...
}
intended to be called as method.
The first invocation would leed to an error since the first argument
getInstance receives is $session, and not a class name.
hth,
joe
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