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difference

perlperl
perlperl asked
on
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Last Modified: 2010-03-05
in object oriented perl
what is is the difference between the foll two variables
NAME and _NAME

sub new
{
  my $proto = shift;
  my $class = ref($proto) || $proto;

  my $this = {};

  bless($this, $class);

  my %hash = @_;

  $this->{NAME} = $hash{NAME} if( defined($hash{NAME}) );

  # set some internal defaults
  $this->{_NAME}    = DEFAULT_NAME;

  return $this;
}



also. what does the following does????
  my $proto = shift;
  my $class = ref($proto) || $proto;
?????
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my $proto = shift;
shift will take the first value of the array off and returns it, shortening the array by 1 and moving everything down.  If no array is provided, will shift @_ within subroutines.  @_ contains the arguments passed to the subroutine.  When creating an object, the first argument to the new function is the class name.
For more:  http://perldoc.perl.org/functions/shift.html


my $class = ref($proto) || $proto;
The ref function will return the type of object, or empty string if no reference is given.  In the case of empty string, the "|| $proto" will return $proto.
For more: http://perldoc.perl.org/functions/ref.html
1) not much. Usually the _var form is used to denote itnernal variables which should not be used by people using your package.

2) new function is passed the class name as the first argument.
therefore
$proto = shift ;
#gets the class or the instance name name.
my $class = ref($proto) || $proto;
#makes it an instance object as well. So, qutoing fro perldoc perltoot, you can say
$me = Person->new() ;
$you = $me->new() ;




oops sorry, dodnt see that it had already been posted and accepted !!

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