I basically need to cycle through all of the numbers from 0000 to 9999 (with leading zeroes). I use the following trivial (if not beautiful) way to accomplish this. 
#!/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 )
                {
                # do something with $i$j$k$l
                }
            }
        }
    }

[download]
Recently someone derided my for implementing the algorithm this way (but didn't suggest a better way of doing it). Does an obviously (to the cognoscenti) better approach exist?

In reply to looping efficiency by Anonymous Monk

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