#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

my $AoH_orig = [ { 'title' => 'aaa-aaa',
                   'name'  => 'tom' },
                 { 'title' => 'bbb-bbb',
                   'name'  => 'kathy' },
                 { 'title' => 'ccc-ccc',
                   'name'  => 'bill' }
                 ];

#try mapping
print Dumper ($AoH_orig);

my $AoH_new = map { $_->{'title'} =~ s/-/_/g } @$AoH_orig;

print Dumper($AoH_orig);