Hi,
This question is for understanding rather than getting it to work.
Let say I want to simply generate all telephone numbers (of length 7).
Update: or else, all words of length X given an alphabet of Y symbols...

#!/usr/bin/perl -w
use strict;

for my $i (0..9) {
    for my $j (0..9) {
        for my $k (0..9) {
            for my $l (0..9) {
                for my $m (0..9) {
                    for my $n (0..9) {
                        for my $o (0..9) {
                            print $i,$j,$k,$l,$m,$n,$o,"\n";
                            }
                        }
                    }
                }
            }
        }
    }

[download]
By using Algorithm::Loops: 

#!/usr/bin/perl -w
use strict;
use Algorithm::Loops qw( NestedLoops );

my @symbol = qw(0 1 2 3 4 5 6 7 8 9);

my @position;
for my $deepness (0..6) {
    push @position, [@symbol];
    }

my @list;
my $iter = NestedLoops(\@position);
    while (@list = $iter->()) {
        print "@list\n";
    }

[download]
I would appreciate very much if one could explain in detail how this Nested Loop works ? I tried many times to complete the code below from scratch and getting nowhere. 

my @symbol=qw(0 1 2 3 4 5 6 7 8 9);
my$deepness=7;

#? Repeat the foreach to specified deepness ?

[download]
Thanks, regards.

In reply to Telephone - Nested Loops by FFRANK

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