TMTOWTDI:

use strict;
use warnings;

for ('Joe Dolly', 'perl.pl', 'States', 'Fred Fillmore Flintstone')
{
    my @got = split;

    if (scalar @got > 1)
    {
        print substr($_, 0, 1) for @got;
        print "\n";
    }
}
[download]

Output:

 2:16 >perl 1835_SoPW.pl
JD
FFF

 2:17 >
[download]

(If this doesn’t accomplish what you want, you will need to explain what you’re really trying to do with that regular expression.)

Update: If you assign [] to an array, that array contains a single element, which is itself a reference to an empty array. I think you meant to rather assign () (the empty list), which leaves the array empty (zero elements).

Hope that helps,