sub find_year {
    my( $str ) = @_;
    my $year;
    $year = $1
        if( $str =~ /\b((?:19|20)\d\d)\b/ );
    return $year
}


for my $title (
    "Let's party like it's 1999",
    "If 6 was 9",
    "If 6 was 9",
    "Summer of 69",
    "Disco 2000",
) {
    print $title , " => ", find_year($title), "\n";
}
[download]

sub find_year {
    my( $str ) = @_;
    my $year;
    $year = $1
        if( $str =~ /\b((?:19|20)\d\d)\b/ );
    return $year
}

#get the title from csv3

open CSV3, "<csv3" or die;

while (<CSV3>) {

  chomp;

  my ($title) = $_ =~ /^.+?,\s*([^,]+?),/; #/ match the title
}

for my $title {
print $title , " => ", find_year($title), "\n"; }
[download]

This second loop creates its own $title variable:

for my $title {
    print $title , " => ", find_year($title), "\n";
}
[download]

What you want instead is to integrate that call to find_year into your while loop:

while( <...>) {
    ...
    my ($title) = ...;

    print "Have title '$title'\n";

    print $title , " => ", find_year($title), "\n";
};
[download]

Ok, thanks that's working nicely now that I'm printing it within the while loop. Is there any way to maintain the variable outside the while loop?