perl hash的hash 拷贝一例

#!/usr/bin/perl
use strict;
use Getopt::Long;
use Pod::Usage;
use File::Copy;
use Data::Dumper;
use Cwd;
use DBI;
use Encode;
use File::BOM qw( :all );

my $hashVer = {};
my $hashV = {'A'=>1,'B'=>2,'C'=>3};
%{$hashVer} = %{$hashV} ;
################################
# $hashVer = $hashV; 注意它们的不同
################################

print Dumper($hashV);
$hashVer->{'A2'}=5;

print Dumper($hashV);
if (%$hashV){
 print "Empty\n"; 
}