CODEWITHSUNDEEP
linuxperlhash
123
123

Reputation: 11216

Why are hash values being printed twice

Problem

Hash values are printed twice in for(each) loop.

Code

use strict;
use warnings;

my %Hash;

my $x=1;

foreach my $item( 1..9 ) {
   $Hash{$x} = $x;
   print scalar keys %Hash,",$item,",$x++,"\n"
}
$x=1;
foreach my $iteml( %Hash){
        print $x++,"\n";
        print "||||$iteml------$Hash{$iteml}||||\n";
}

print "@{[%Hash]}\n";

Output

1,1,1
2,2,2
3,3,3
4,4,4
5,5,5
6,6,6
7,7,7
8,8,8
9,9,9
1
||||6------6||||
2
||||6------6||||
3
||||3------3||||
4
||||3------3||||
5
||||7------7||||
6
||||7------7||||
7
||||9------9||||
8
||||9------9||||
9
||||2------2||||
10
||||2------2||||
11
||||8------8||||
12
||||8------8||||
13
||||1------1||||
14
||||1------1||||
15
||||4------4||||
16
||||4------4||||
17
||||5------5||||
18
||||5------5||||
6 6 3 3 7 7 9 9 2 2 8 8 1 1 4 4 5 5

Question

Why is this happening?

Version

v5.10.0 built for x86_64-linux-thread-multi

Upvotes: 1

Views: 136

Answers (1)

zdim
zdim

Reputation: 66891

For one, you iterate over the hash itself, (%Hash). So you are getting keys and values, the list.

What makes it interesting is that the hash has the same keys and values. So it prints the key and its value, which is the same. Then it prints the value, and then uses it as the key ... which is a valid key, and with the same value. So it looks like it prints it twice :)

Upvotes: 9

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