Question

sub getHeading
{
    my $var = $_[0];
    my $match;
     if ($match = ($var =~ m/$fivetonine/))
     {
        return "=";
     }
     if ($match = ($var =~ m/$tentofourteen/))
     {
        return "==";
     }
     if ($match = ($var =~ m/$fifteentonineteen/)){
        return "===";
     }
     return "===";
}
my $ref_to_getHeading = \getHeading;

and I am calling it via:

$html =~ s/(.*)<font size="([^"]+)">(.+)<\/font>(.*)/$ref_to_getHeading($2)$1$3$4$ref_to_getHeading($2)/m;

I am wanting to pass a string in to this function, I want to check if it is one of 3 different matches and return the appropriate number of = signs, I am doing this wrong but I can’t figure out how to make it take parameters? I get a run time error saying $var is initialised? I tried using @_ but I don’t really understand what the difference is.

Any help much appreciated, I have never written perl before and this is my first real program.

Answer 1

Double mistake there.

First, you aren’t taking a reference to a function – You need to add the ampersand.

But even if you do that, it won’t work. You are missing the /e flag in your substitution: You can’t dereference a coderef within a string like you’d normally do with (scalar|hash|array)ref:

my $example = sub { return "hello" };
say "$example->()"; #Will stringify the coderef.

You either need the /e flag,

$html =~ s/etc/$ref_to_getHeading->($2) . "$1$3$4" . $ref_to_getHeading->($2)/em;

Or a little trick:

$html =~ s/etc/@{[$ref_to_getHeading->($2)]}$1$3$4@{[$ref_to_getHeading->($2)]}/m;

EDIT: Gosh, am I a slow typist..
Anyhow, with either way, you should be able to call the sub directly, so no need for the coderef.