Why is my sort function not working - arrays

Question

I have a file which I have read into an array, with multiple columns and I want to sort numerically by the second column. I've looked up countless similar questions and tried to directly incorporate the answers given.
here is the basic code I am using:
use strict;
use warnings;
use diagnostics;
my #arrayed = (
"\ndog", "10", "barks",
"\ncat", "20", "meows",
"\nfish", "5", "plop",
"\nant", "30", "walk",
);
print "#arrayed";
print "\n";
my #sortedarray = sort { $a->[1] <=> $b->[1] } #arrayed;
print "#sortedarray";
exit;
This gives me an error cant use string ("dog") as an array reference while strict is turned on. I tried a few other examples with other files, arrays but always get this message so I assume there must be something intrinsically wrong with my code.
could anybody more experienced shed a little light on what I'm doing wrong please, and allow me to sort by the numbered column while still maintaining the row structure.

Answer 1

You have a flat array, but you want an array-of-arrays:
use strict;
use warnings;
use diagnostics;
use Data::Dumper;
my #arrayed = (
["dog", "10", "barks"],
["cat", "20", "meows"],
["fish", "5", "plop"],
["ant", "30", "walk"],
);
print Dumper(\#arrayed);
my #sortedarray = sort { $a->[1] <=> $b->[1] } #arrayed;
print Dumper(\#sortedarray);
__END__
$VAR1 = [
[
'dog',
'10',
'barks'
],
[
'cat',
'20',
'meows'
],
[
'fish',
'5',
'plop'
],
[
'ant',
'30',
'walk'
]
];
$VAR1 = [
[
'fish',
5,
'plop'
],
[
'dog',
10,
'barks'
],
[
'cat',
20,
'meows'
],
[
'ant',
30,
'walk'
]
];

Answer 2

Your assignment does not create a multi-dimensional array:
my #arrayed = (
"\ndog", "10", "barks",
"\ncat", "20", "meows",
"\nfish", "5", "plop",
"\nant", "30", "walk",
);
You would need to use array references inside those parentheses:
my #arrayed = (
[ "\ndog", "10", "barks" ],
[ "\ncat", "20", "meows" ],
[ "\nfish", "5", "plop" ],
[ "\nant", "30", "walk" ]
);
The brackets [ ... ] create anonymous array references, which can then be stored in the array.
One of the most important things to know when debugging is what your data looks like. Doing something like what you did
print "#arrayed";
Is not very useful, since it will only show a list of the elements separated by space. Also, if you had done this with a multi-dimensional array, you would get output like this:
ARRAY(0x7fd658) ARRAY(0x7fd7f0)
Which is what array references look like when stringified. Instead, you should use the Data::Dumper module:
use Data::Dumper;
print Dumper \#arrayed;
Notice that you are printing a reference to the array. The output would be a data structure looking like what toolic has shown in his answer:
$VAR1 = [
[ ...
Note that the brackets, again, denote array references.