in reply to Running out of memory while running this for loop

I am also running out of memory before the loop completes.

What is your idea of $aref in that loop that bombs off? Is it an integer, or an array reference? What it the result of adding 1 to an array reference? or 2 ? What happens to an array (or array reference) if you index it with the result of that addition? 

my $aref = [];
print $aref,"\n";
print $aref + 1,"\n";
print $aref + 2,"\n";
print "mem: ",qx{ps -o vsz= $$};
$aref[$aref +2] = "foo";
print "mem: ",qx{ps -o vsz= $$};
__END__
ARRAY(0xf5dba0)
16112545
16112546
mem:  28964
mem: 154844

[download]

By converting the hexadecimal address of $aref to integer - this is what happens if you add an integer to it - and using it then as an index, you extend @data and pre-allocate slots, each containing a NULL value. If the address of $aref is high enough, your program hits the memory limit of your machine.

perl -le'print map{pack c,($-++?1:13)+ord}split//,ESEL'

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Re^2: Running out of memory while running this for loop
by Ppeoc (Beadle) on Nov 01, 2015 at 21:57 UTC
    Yes! You are right. Thank you for catching that error. I was adding index value to array reference. How can I change my for loop to make it work?
[reply]

      The "Perlish" way to iterate element-by-element over an array is: 

      c:\@Work\Perl\monks>perl -wMstrict -le
"my @array = qw(zero one two three);
 ;;
 for my $element (@array) {
   print qq{element '$element'};
   }
"
element 'zero'
element 'one'
element 'two'
element 'three'

      [download]
      If each "element" of  @array is actually an array reference, you might then need to iterate in turn over the referenced array in similar fashion: 
      c:\@Work\Perl\monks>perl -wMstrict -le
"my @array = (
   [ 1, 2, 3,    ],
   [ 'v' .. 'z'  ],
   [ qw(one two) ],
   );
 ;;
 for my $arrayref (@array) {
   for my $element (@$arrayref) {
     printf qq{'$element' };
     }
   print '';
   }
"
'1' '2' '3'
'v' 'w' 'x' 'y' 'z'
'one' 'two'

      [download]
      Please see perldsc for more info and examples.

      Give a man a fish:  <%-{-{-{-<

[reply]
[d/l]
[select]
        Thank you so much! I now understand what I was doing wrong. Got it to work with the following piece of code 
        for my $i ( 2033 .. $#data ) {
    if (($i-$n)%6267== 0)
    {
        $color = $data[$i][0];
        $order= $data[$i+1][0];
        $shape = $data[$i+3][0];
        $name = $data[$i+4][0];        
        }
        print $out_ph1 $predata,",", $color,"," ,$order,"," ,$shape,",
+" ,$name,",";
     for  my $j ( 4 .. $#{ $data[$i] } ) {
         print $out_ph1 $data[$i][$j],"\_";
     }
        print $out_ph1 "\n";    
 }

        [download]
        Thank you monks!
[reply]
[d/l]

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