Reference and DeReference

sampleRef2.pl

#!/usr/bin/perl
# -*- coding:utf-8 -*-

use strict;
use warnings;
use feature 'say';
use encoding 'utf-8';

my @array = (1,2,3);
my %hash = (
	'A'=>'Alpha',
	'B'=>'Bravo',
	'C'=>'Charlie'
	);

say 'foreach:File Scope';
foreach my $a (@array){
	say $a;
}

say 'foreach:File Scope';
foreach my $k (keys(%hash)){
	say $hash{$k};
}

sub _push1 {
	my $temp_arr = shift;
	my @arr = @$temp_arr;
	push(@arr,4);
	say 'foreach:Sub Scope';
	foreach my $a (@arr){
		say $a;
	}
}

sub _push2 {
	my $arr = shift;
	push(@$arr,4);
	say 'foreach:Sub Scope';
	foreach my $a (@$arr){
		say $a;
	}
}

&_push1(\@array);
say 'foreach:File Scope';
foreach my $a (@array){
	say $a;
}

&_push2(\@array);
say 'foreach:File Scope';
foreach my $a (@array){
	say $a;
}

sub _add1 {
	my $temp = shift;
	my %hs = %$temp;
	$hs{'D'} = 'Delta';
	say 'foreach:Sub Scope';
	foreach my $key (keys(%hs)){
		say $hs{$key}
	}
}
&_add1(\%hash);
say 'foreach:File Scope';
foreach my $k (keys(%hash)){
	say $hash{$k};
}

sub _add2 {
	my $hs = shift;
	$$hs{'D'} = 'Delta';
	say 'foreach:Sub Scope';
	foreach my $key (keys(%$hs)){
		say $$hs{$key}
	}
}
&_add2(\%hash);
say 'foreach:File Scope';
foreach my $k (keys(%hash)){
	say $hash{$k};
}