CODEWITHSUNDEEP
arraysperlreference
user2335015
user2335015

Reputation: 121

Problems with array references in perl

I am trying to count how many time DE10 and each of the keys in my ICD10 hash occurs in the same line in my file2.tsv. I further have to divide it by male/female (M/K). I therefore made a hash called results. Each of the keys in this is named after the key in the ICD10 hash, and they refers to an array of 2 elements, the first counting the male, the second counting the females.

But I get this warning:

Can't use string ("0") as an ARRAY ref while "strict refs"

due to this line:

  $results{$key}[1] +=1;

I am a little weak on this reference part, can someone help me with my mistake? thanks a lot

#!/usr/bin/perl -w
use strict;

###################
# loading my hash #
###################

my %icd10;

open(IN, '<', 'myfile.tsv') or die;
while (defined (my $line = <IN>)) {
chomp $line;
$icd10{$line} = 1;
}
close IN;

################
### COUNTING
#################

my %results;

open(IN, '<', 'myfile2.tsv') or die;
while (defined (my $line = <IN>)) {
chomp $line;
my @line = split('\t', $line);
my %hash;
for (my $i = 2; $i < scalar(@line); $i++){ 
    $hash{$line[$i]} = 1;
}

if (grep (m/^DE10/, keys %hash)) {
    foreach my $key (keys %icd10){
        if (grep (m/^$key/, keys %hash)) {
            if (exists $results{$key}) {
                if ($line[1] eq 'M') {
                    $results{$key}[1] +=1;
                }
                elsif ($line[1] eq 'K'){
                    $results{$key}[2] +=1;
                }
            }
            else{
                if ($line[1] eq 'M') {
                    $results{$key}=(1,0);
                }
                elsif ($line[1] eq 'K'){
                    $results{$key}=(0,1);
                }
            }

Upvotes: 1

Views: 96

Answers (1)

Lee Duhem
Lee Duhem

Reputation: 15121

If you want $results{$key} to be a reference to an array, then the parentheses in these two identical sentences $results{$key}=(1,0); should be square brackets, like this: $results{$key}=[1,0];.

To create a reference to an array, you can use backslash operator:

$arrayref = \@array;

To create a reference to an anonymous array you should use square brackets:

$arrayref = [ 'ele1', 'ele2' ];

See perlref for further details.

Upvotes: 2

Related Questions