Array won't print

[jpaterso]

Here's the code. When I run it, the array prints fine in the while loop but I get the last person in every array element in the for loop.

Thanks in advance.



File:

Jerry,12
Lon,11
Jon,10
Mike,9

Perl code (on linux)

#!/usr/bin/perl
open (FILE, "try.txt");
$x = 0;
while(<FILE>) {
    chomp;    
    ($STUDENT,$GR)= split(/,/);
$hold[$x,1] = $STUDENT;
$hold[$x,2] = $GR;
print "$x: $hold[$x,1],$hold[$x,2]\n";
$x = $x+1;
 
}
close(FILE);
for ($i = 0; $i < 4; $i++){
print "$i --  NAME--$hold[$i,1],GRADE--$hold[$i,2]\n";
} 
;
 

[KevinADC]

Unless you are using Perl 6 and the array syntax is valid for perl 6, your code is not valid for other versions of perl. It looks like you want to create a multi-dimensional array, with perl 5.x you can do it like this:

use warnings;
use strict;
 
open (FILE, "try.txt");
my $x = 0;
my @hold = ();
while(<FILE>) {
   chomp;    
   push @hold, [split(/,/)];
}
close(FILE);
for my $i (0..$#hold){
   print "$i --  NAME -- $hold[$i][0],  GRADE -- $hold[$i][1]\n";
} 

If you are using perl 6, I am not familiar with it so can't answer why the code does not work.

[jpaterso]

Thanks,

I have been out of the tech game for 3 years so I am not sure what version the school district uses (they dumped the linux platform in lieu of windows). I will try you solution tomorrow and see what happens.

[Ganon11]

It seems like you would be much better off using a hash instead of a 2D array:

#!usr/bin/env perl
use warnings;
use strict;
 
open (FILE, "try.txt");
my $x = 0;
my %hold = ();
while(<FILE>) {
   chomp;   
   my ($name, $grade) = split(/,/);
   $hold{$name} = $grade;
}
=close(FILE);
for my $name (keys %hold){
   print "NAME: $name, GRADE: $hold{$name}\n";
}

[jpaterso]

Awesome! It works like a charm. I went with the array (because I am used to it and I need to do other things).

Thanks again. Great forum!

[KevinADC]

The considerations are:

Hashes do not maintain original order and the last instance of a duplicate key will be the only one left.

The multi-dim array method retains order and duplicates.

Which method to use depends on the requirements of the program.