Come for the quick hacks, stay for the epiphanies. | |
PerlMonks |
Re: while nested in foreach ($_ pitfalls)by Russ (Deacon) |
on Dec 01, 2003 at 17:54 UTC ( [id://311333]=note: print w/replies, xml ) | Need Help?? |
When I read the subject ("while nested in foreach"), I thought this would be a different problem. Just for grins, here is a "gotcha" to watch for: resetting $_.
In this example (perl 5.8.0), the second print statement shows an empty $_ because the diamond operator (in the while loop) overwrote $_ (as we told it to do). So, after the nested while loop, we no longer have the old value in $_ (the counter in the for loop). Exercises left for the reader: replace the while loop with other $_-using constructs and see how they behave... Most perl built-ins, and many CPAN modules, are "smart" enough to localize $_ to prevent confusion, but not all.
In Section
Seekers of Perl Wisdom
|
|