Question

Should a subroutine croak when called with more arguments than expected or should the extra arguments simply be ignored?

#!/usr/bin/env perl
use warnings;
use strict;


sub routine {
    my ( $a, $b ) = @_;
    return $a * $b;
}

my $reslult = routine( 4, 5, 6 );

Answer 1

Generally I don’t bother writing argument checks by hand, but I think the correct response is to croak. That way you can extend the function to take optional arguments later without breaking existing callers.

If your Perl is new enough, you can install and use Function::Parameters like this:

use warnings;
use strict;
use Function::Parameters qw(:strict);

fun routine($x, y) {
    return $x * $y;
}

my $result = routine(4, 5, 6);  # croaks automatically

(Btw, don’t call your variables $a or $b: those names are used by sort and exempt from strict 'vars' checks.)