Even the fragment shows some of your problems... that is, it would, with use strict; use warnings and a few print statements to see what your vars actually hold:

#!/usr/bin/perl
use 5.014;       # functional equiv to use strict; use warnings; for t
+his demo
# 985557

my ($x, @array, $index, $arr_ref, @arr);

sub sub1{
    for $x (0 .. 3){
    $array[$x] = 0;
    }
    say "\t from sub \$array[\$x]: |$array[$x]|";

# omit the part for generating the array;

    return \@array;
}

####################### main part

for ($index=0; $index<2; $index++){
    $arr_ref = &sub1($index);
    $arr[$index] = @$arr_ref;

    foreach $_ (0 .. 3){
        say "\@arr | @arr |, \$index: |$index|, \$_: |@_|";
       # print "$arr[$index][$_]\n"; 
       # Can't use string ("101") as an ARRAY ref while "strict refs" 
       # in use at 985557.pl line 24.
    }
    say "\@arr | @arr |, \$index: |$index|, \$_: |@_|";
}
say "\@arr | @arr |, \$index: |$index|, \$_: |@_|";

[download]

No, this won't bork your system; TITS -- " ...try it to see!"

And for your next step toward mastery, learning the debugger will be a help; better, in most cases than sticking in print statements, willy-nilly, as above.

In reply to Re: Question about how to return a array in subroutine to form a two dimensional array by ww
in thread Question about how to return a array in subroutine to form a two dimensional array by mianfeidewucan

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