refers to the hash variable type in Perl. Other languages call this a dictionary or associate away.
Questions tagged [perl-hash]
64 questions
1
vote
1 answer
Cannot fire subroutine inside a hash of subroutines in perl
Hi I'm quite new to perl. I have a perl hash containing subroutines. I've tried to run it in various ways that I found online. But nothing seems to work.
My code :
%hashfun = (
start=>sub { print 'hello' },
end=>sub { print 'bye' }
);
And I've…
Ihsan Izwer
- 123
- 1
- 10
1
vote
1 answer
dereferencing nested hash perl
If I declare a hash like this:
my %n = (a => {1 => "1a",2 => "2a"},"b" => {1 => "1b",2 => "2b"});
How do I access the data in: n -> a -> 1?
I tried
print "$n{a{1}}";
print "$n{a ->{ 1}}";
These two don't work
Tapajit Dey
- 1,048
- 2
- 10
- 20
1
vote
1 answer
How to copy a nested hash
How to copy a multi level nested hash(say, %A) to another hash(say, %B)? I want to make sure that the new hash does not contain same references(pointers) as the original hash(%A).
If I change anything in the original hash (%A), it should not…
gsinha
- 1,073
- 2
- 16
- 36
1
vote
1 answer
Perl hash giving undef values
If was trying to write a piece of code using perl hash. There are no undefined values or new lines in __DATA__(tried giving same input from file also). But while printing using data dumper or the traditional way I am getting a '' as key and undef…
aravind ramesh
- 307
- 2
- 11
1
vote
1 answer
Accessing elements in hash of hash of arrays in perl
my %PlannedPerWeek = (
September => {
Week1 => [80, 23, 199, 45, 19, 36],
Week2 => [78, 21, 195, 43, 18, 36],
Week3 => [76, 19, 191, 41, 17,…
Ram
- 1,043
- 3
- 15
- 30
1
vote
3 answers
How do I assemble a hash of hashes piece-wise, not up-front?
I want to create a structure of hashes within hashes in Perl, but all tutorials (like chapter 9.4. Hashes of Hashes in Programming Perl) add them all upfront. I want to initially create the structure and then fill in the empty hashes using…
user1512947
- 11
- 1
0
votes
3 answers
Shorten code: merge arrays from hashes
I have a list of hashes and some of the hashes contain a key which provides an array itself.
my @cars = (
{ # empty car
name => "BMW",
},
{ # car with passengers
name => "Mercedes",
passengers => [qw(Paul Willy)],
},
…
Daniel Böhmer
- 12,527
- 5
- 31
- 45
0
votes
2 answers
Initializing hash of arrays
I wanted to have a hash of arrays of counters, with initial values of 0.
Here is my first attempt at the code:
my @names = ("", a, b, c);
my %hsh = ();
for $i (1..3)
{
# I expected this line to give me a fresh new array each time - it did not.
…
T G
- 376
- 2
- 7
0
votes
1 answer
Perl: How to make hash of hash where keys come from an array
I want to make a hash of hash using the structure of an array. Each array element should be a subkey of the preceding array element. For example using the following arrays:
@array1 = ("animal","dog","sparky");
@array2 =…
Westrock
- 171
- 4
- 13
0
votes
2 answers
How to parse multiple csv files with Perl and print only the unique results
I have a bunch of csv file in a simple format say 'Name,Country,Currency'. I need to read all of them and print only the unique union. If they show up in few files they are identical. Tried to use Hash::Merge but seems to be working only for two. I…
rolleikid
- 13
- 1
0
votes
2 answers
How can I store one element of a two dimensional in another hash?
I have a two dimensional hash.
myHash = (
'a' => {
'a1' => v1
'a2' => v2
}
'b' => {
'b1' => v3
'b2' => v4
}
);
I want to retrieve a hash like this:
%hashSlice = %Hash{'a'};
Where hashSlice should…
Vishrut Maheshwari
- 11
- 1
0
votes
2 answers
Find average of hash values Perl
I am looking to return an average of the hash values (per key) below (grades.txt)
Melotti, Suzanne: 100 100 95 95 92 87
Wayne, Bruce: 85 85 85 75 75 75
Stark, Tony: 92 92 75 79 91 87
Odinson, Thor: 23 12 10 42 50 64
Kane, Kathy: 100 100 100 100 95…
Chantz Baudoux
- 19
- 3
0
votes
2 answers
How do I merge two hashes that start with different keys in Perl?
I have to hashes as follows:
my %hash1 = (
'modules' => {
'top0' => {
'instances' => {
'sub_top' => {
'instances' => {
'inst2' => 2,
'inst0'…
Vishwasu Deshpande
- 49
- 5
0
votes
3 answers
How can I iterate through nested hash of hash without knowing its key?
I have a hash of hashes, that is, hash and hash references in my data structure. Can I iterate through the deepest hash when I only have the main hash name and no key of the deepest hash?
my %gates_info=(
'order' => {
'nand' => {
…
programmingzeal
- 145
- 7
0
votes
1 answer
Accessing and printing Hash of array
I have a question of how to print a hash:
@language(1,2,3);
for my $i (0 .. $#language)
{
$statement = $db->selectall_arrayref(
"select word from words
left outer join language
on words.languageId = language.languageId
where…
JoT
- 303
- 1
- 3
- 10