Passing arrays to a subroutine that prints each array separately

Question

I know that this is probably a simple fix, but I have not been able to find the answer through google and searching through the questions here.

My goal is to pass multiple arrays to a subroutine that simply iterates through each array separately and prints each array with something before and after it.

What I have:

@A1 = (1, 2, 3);
@A2 = (4, 5, 6);

printdata(@A1, @A2) ;

sub printdata {
   foreach(@_) {
      print "$_" ; 
      print "@@@"
      }
   }

What I am attempting to get is:

123@@@456@@@

Instead its treating both arrays as one and iterating through each variable in the array, Putting the separator after every variable vice the entire array.

1@@@2@@@3@@@etc.....

I am not sure how to get the subroutine to treat the arrays as separate rather than as one.

Any Help would be greatly appreciated!

Answer 1

You need to pass the arrays as references:

@A1 = (1, 2, 3);
@A2 = (4, 5, 6);

printdata(\@A1, \@A2) ;

sub printdata {
   foreach(@_) {
      print @$_ ; 
      print "@@@"
      }
}

The sub call expands the arrays into a list of scalars, which is then passed to the sub within the @_ variable. E.g.:

printdata(@A1, @A2);

is equal to:

printdata(1,2,3,4,5,6);

Answer 2

See the section on "Pass by Reference" in perldoc perlsub.