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

my $hashRef = {};
my $string = "Tom, 18, Jack, 22, Tim, 30";
populateHash($hashRef,$string);

sub populateHash{
        my ($hashRef,$scopedString)  = @_;
        my @stringArray = split (', ',$scopedString);
        %$hashRef = @stringArray;
        return $hashRef;
        }

use Data::Dumper;
print Dumper(\%$hashRef);