RE: Re: require problems

Well, not really *that* criminal --

it's a non-empty list...

<INCORRECT>
lists in scalar/boolean context return the number of their elements.
</INCORRECT>;

Update: I humbly acknowledge the folly of the above statement.

Should be:

list assignment returns the number of elements.

End Update

Thus:

perl -e '$val = () = 0; print $val';
[download]

prints 1 -- true!

Comment on RE: Re: require problems Download Code

Replies are listed 'Best First'.
NEVER a list in a scalar context -- PLEASE! by merlyn (Sage) on Sep 19, 2000 at 22:24 UTC
lists in scalar/boolean context return the number of their elements. Oh. Once again, trying to dispel the myth of that statement. Repeat after me: You can never have a list in a scalar context... You can never have a list in a scalar context... You can never have a list in a scalar context... Now, what's really happening is that you have a list assignment operator in a scalar context, which is defined as having a return value of the number of elements copied across, while giving a list context to the right side. In this case, the right side is a simple expression, which gets turned into a list of one element. So we get a "1" for the return value. Once more, just so you remember: You can never have a list in a scalar context... -- Randal L. Schwartz, Perl hacker	[reply]
RE: RE: Re: require problems by Adam (Vicar) on Sep 19, 2000 at 22:31 UTC
What these two gurus are trying to say is that there is a HUGE difference between lists and arrays. Please don't confuse them. An array in scalar context returns the number of elements therein.	[reply]
RE: RE: Re: require problems by japhy (Canon) on Sep 19, 2000 at 22:22 UTC
No, that's not true. Lists do not exist in scalar or boolean context. `$a = (3,2,1); print $a; # 1` [download] Read my article ("List is a Four-Letter Word") at my web site for stuff I'd rather not rewrite here. `perl -e '$val = () = (10,20,30); print $val'` [download] prints 3. `$_="goto+F.print+chop;\n=yhpaj";F1:eval`	[reply] [d/l] [select]