Iterating over an array

Question

Possible Duplicate:
automatically get loop index in foreach loop in perl

I'd like to iterate over an array, but I need to keep track of the index. This code doesn't list the indexes as I'd expect - how can I fix it?

$arr = [0,0,0,0];
foreach $i (0 .. scalar @$arr) { print $i; }

Answer 1

Actually it works. Just noticed that re.pl is hiding my output. Printing "$i\n" works of course.

Answer 2

To get a range of indexes for the array use 0 .. $#$arr.
scalar @$arr returns the number of elements in the array.

Answer 3

To add to eugene's answer: a little more standard way is

for( my $i = 0; $i <= $#$arr ; $i++)  { 
   ...
}

Answer 4

From Perl 5.12 you can use each on an array:

use 5.012;
use warnings;

my @array = 'a' .. 'h';

while (my ($i, $val) = each @array) {
    say "$i => $val";
}

For some more info see blog post: each @array in Perl 5.12

/I3az/