[Pdx-pm] for vs foreach question

Thomas Keller kellert at ohsu.edu
Wed Dec 10 13:17:53 CST 2003

Basically, it is a matter of understanding what is $_ in the foreach 
loop. I forgot that it would be the actual element of my arrays rather 
than the index; whereas in the for loop I defined the indices 
Sigh. But it doesn't hurt to rethink about the basics now and then.
Thanks all.

On Dec 10, 2003, at 11:00 AM, Jeff Zucker wrote:

> Thomas Keller wrote:
>> Hi all,
>> I thought the "foreach" keyword was a synonym for the "for" keyword. 
>> So I'm perplexed why the following loops don't give the same output:
> First, I think if you add "each" to the "for" in the first loop, it 
> will continue to work and if you take off "each" from the second loop, 
> it will continue to not work.  The use of "for" or "foreach" is not 
> relevant to your problem.
> Here is the second loop written correctly with more legible variable 
> names so you can see what's going on:
> my $table = $aref;
> for my $row (@$table) {
>    foreach my $column (@$row) {
>        print $column, " ";
>    }
>    print "\n";
> }
> Write back if that doesn't clarify things for you.
> -- 
> Jeff

More information about the Pdx-pm-list mailing list