A lot of people seem to think it is, but it's not.

• $|++ adds one to the current value of $|.
• $| = 1 sets the value of $| equal to one.

$| = 1 is much safer and more straight forward (less ambiguous?).

Update: Whoops. I was way wrong. A thousand lashes to me for misleading my fellows due to my neglectful ignorance. Thanks to dvergin for the correction and for setting me straight..

Cheers!

Brent

-- Yeah, I'm a Delt.

      If for some reason $| = -1,...

No. Please don't make assertions like that when you haven't tested them.

$| is magic. It always equals either zero or one. Nothing else. Behold:

print "$|\n";      # 0

$| = -1;
print "$|\n";      # 1

$|++;
print "$|\n";      # 1

$|++;
print "$|\n";      # 1

$|--;
print "$|\n";      # 0

$|--;
print "$|\n";      # 1

$|--;
print "$|\n";      # 0
[download]

As you can see, $|++ always sets $| to one (no matter what it was) and $|-- always toggles it.

I agree that $| = 1; is more clear to newer programmers. But rationalle for that usage has to do with the learning curve and not with the behavior of $|.

------------------------------------------------------------
"Perl is a mess and that's good because the
problem space is also a mess." - Larry Wall

Makes perfect sense, but under what circumstances would $|=-1, unless those where you specifically defined it as such? I can see where it would be a much better idea to use $|=1 so you don't mistakenly define $| to 2 (or higher).

OTOH, why haven't more folks discussed the use of the FileHandle or IO modules that support the autoflush method? Wouldn't that negate this argument altogether?

-fuzzyping

      so you don't mistakenly define $| to 2...

That won't happen. See my response to dorko for a demonstration of the magical character of $|.