Perl array and string as method arguments - arrays

Question

I have a method where I give two arguments: one array and one string. The problem is when I initialise two different variables, one for the array and one for the string, I get the first element of the array in the first variable and the second element in the second variable. My question is how can I get the whole array in a variable and the string in a different variable?
Analyze.pm
sub analyze {
my $self = shift;
my ($content, $stringToSearch) = #_;
# my ($stringToSearch) = #_;
print "$stringToSearch";
if (!defined($stringToSearch) or length($stringToSearch) == 0) { die 'stringToSearch is not defined yet! ' }
foreach my $element ($content) {
#print "$element";
my $loc = index($element, $stringToSearch);
# print "$loc\n";
given ($stringToSearch) {
when ($stringToSearch eq "Hi") {
if ($loc != 0) {
print "Searched word is Hi \n";
} else {
print "No word found like this one! "
}
}
#when ($stringToSearch == 'ORIENTED_EDGE') {
# print 'Searched word is ORIENTED_EDGE';
#} # Printed out because i dont need it now!
}
break; # For testing
}
}
example.pm
my #fileContent = ('Hi', 'There', 'Its', 'Me')
my $analyzer = Analyze->new();
$analyzer->analyze(#fileContent, 'Hi');
When I change $content to #content it puts all the values of the array and the string in #content
I hope someone is able to help me. I'm a beginner in Perl. Thanks in advance

Answer 1

You can't pass arrays to subs (or methods), only a list of scalars. As such,
$analyzer->analyze(#lines, 'Hi');
is the same as as
$analyzer->analyze($lines[0], $lines[1], ..., 'Hi');
It means that the following won't work well:
my (#strings, $target) = #_;
Perl doesn't know how many items belonged to the original array, so it places them all in #strings, leaving $target undefined.
Solutions
You can do what you want as follows:
sub analyze {
my $self = shift;
my $target = pop;
my #strings = #_
for my $string (#strings) {
...
}
}
$analyzer->analyze(#lines, 'Hi')
Or without the needless copy:
sub analyze {
my $self = shift;
my $target = pop;
for my $string (#_) {
...
}
}
$analyzer->analyze(#lines, 'Hi')
Passing the target first can be easier.
sub analyze {
my ($self, $target, #strings) = #_;
for my $string (#strings) {
...
}
}
$analyzer->analyze('Hi', #lines)
Or without the needless copy:
sub analyze {
my $self = shift;
my $target = shift;
for my $string (#_) {
...
}
}
$analyzer->analyze('Hi', #lines)
You could also pass a reference to the array (in any order you like) since a reference is a scalar.
sub analyze {
my ($self, $target, $strings) = #_;
for my $string (#$strings) {
...
}
}
$analyzer->analyze('Hi', \#lines)
I would go with the second to last. It follows the same general pattern as the well-known grep.
my #matches = grep { condition($_) } #strings;

Answer 2

I'd just like to add a slightly different method of passing an array to a subroutine.
# Begin main program
my #arr=(1,2,3);
my $i=0;
mysub(\#arr,$i); # Pass the reference to the array
exit; # Exit main program
##########
sub mysub
{my($aref,$i)=#_; # We are receiving an array ref.
my #arr=#$aref; # Now we are back to a regular array.
print "$arr[0]\n$arr[1]\n$arr[2]\n";
return;
}