Re: process array with while loop

This is bad practice.If you read perlop: I/O Operators carefully you'll see < > are special for filehandles. You'll most likely run into weird problems if the list is empty.

Also qw does not need (or want) commas. It should be more like:

use strict;
use warnings;
my @array = qw( blue red orange brown );
foreach (@array) {
  print "$_\n";
}
[download]

grep

One dead unjugged rabbit fish later

Comment on Re: process array with while loop Select or Download Code

Replies are listed 'Best First'.
Re^2: process array with while loop by reason2006 (Novice) on Nov 09, 2006 at 17:23 UTC
Thanks guys. I'll switch to using foreach.	[reply]
Re^3: process array with while loop by suaveant (Parson) on Nov 09, 2006 at 18:30 UTC
There is one time when you will want to use a while loop for an array (that I can think of) and that is if you are adding items to the array while iterating through it. for(each) will not reflect changes to the array once the loop has started. A good example of something like this is traversing a directory structure.... `#This code not tested my @dirs = '.'; while(my $dir = shift @dirs) { opendir(DIR,$dir); while(my $entry = readdir(DIR)) { if(-d $entry) { push @dirs, "$dir/$entry"; } else { #do something for files/links etc } } closedir(DIR); }` [download] Just thought I would point that out. for basically makes an in-memory copy of the list when it first starts. - Ant - Some of my best work - (1 2 3)	[reply] [d/l]
Re^4: process array with while loop by ikegami (Patriarch) on Nov 09, 2006 at 18:46 UTC
In order to to allow `""`, `0`, undef, etc in the array, the general form would be `while (@array) { my $item = shift @array; # or pop ... push(@array, ...); # or unshift ... }` [download] (It's not a problem in your case since every item in `@dirs` starts with `.`.) This model is useful to perform recursive processes without using recursion.	[reply] [d/l] [select]


P is for Practical
	PerlMonks