Does anyone know if while loops could be used like this while (@array){};

That's possible, and will repeat the block while @array is true. @array in scalar context returns the number of elements, so this will loop while @array has elements. If you don't remove elements from it, it wil loop indefinitely.

With Perl, you can create any loop you want. There's a number of useful loop forms already: while, do while, do until, and two kinds of for(each). If that's not sufficient for whatever you want (you didn't really describe what you want), you can create any loop yourself. Bare blocks are considered loops, but they are executed only once if you don't change that yourself. You can use redo and last together with if and unless to construct your very own, very specific loop.

U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

You might want to reconsider for and foreach, or better yet try to give a more thorough explanation of why you believe you cannot use them.

--
perl -pe "s/\b;([st])/'\1/mg"

Yes, but that code fragment won't do what you expect.

There are lots of ways to do things in Perl. Please say more about what, exactly, you're trying to do.

my $count = 10;
while ($count) {
    #do something to array
    print $array[$count--];
}

# alternative

$count =0;
for (@array) {
   print "$count $_\n"; # $_ is the current array item
   $count = &something_complex;
}
[download]

my $count =0;
while(1) {
   # do something to the array
   $count = &something_strange
   last if (test_exit_condition); 
}
[download]

If you need a real infinite loop, then this one could suit you better:

Or the expressionless C-style loop. (The while(1) loop will be converted into it to optimize, so why not type it yourself?) They're a nice visual way to say: this is infinite, while while(1) and while(0) don't differ a lot.

for (;;) {
    # ...
}
[download]

U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

<pedant class="minor">
The while(1) loop will be converted into it to optimize

Im fairly sure that if you look into the documentation again that the c style for loop is actually converted into a while() block. Not the other way round.

Hmm, just doublechecked perlsyn and it seems that they arent clear, nor is the camel, as to whether these are actually handled internally as forms of each other. However the camel has the following interesting addition to the perlsyn:

The for loop can be defined in terms of the corresponding while loop.

Thus, the following:

for ($i = 1; $i < 10; $i++) {
    ...
}
[download]

is the same as:

$i = 1;
while ($i < 10) {
    ...
}
continue {
    $i++;
}
[download]

(Defining the for loop in terms of a continue block allows us to preserve the correct semantics even when the loop is continued via a next statement. This is unlike C, in which there is no way to write the exact equivalent of a continued for loop without chicanery.)

<super>emphasis added by me</super>
</pedant>

Yves / DeMerphq
---
Writing a good benchmark isnt as easy as it might look.

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

my @array = (1..15);

print "Numbers are ",join(", ",@array),"\n";

foreach(@array){
    next if $_ % 2;     # Skip odd numbers.
    last if $_ > 10; # Exit loop prematurely.
    $_ = $_ * 2;
    
}

print "Numbers now ",join(", ",@array),"\n";
[download]

The reason why I'm not using for or foreach is because I need to change the loop control variable...

foreach my $foo (@bar) {...} works just as while my $baz (@quux) { } does. perldoc perlsyn