--- Bryan Harris <[EMAIL PROTECTED]> wrote:
> Wild, I had no idea perl supported all these notations...
LOL!!! There are more....
TMTOWTDI: There's More Than One Way To Do It.
> >> I'd like to concatenate two variables--
> >> $newVar = $old1 . $old2;
> >> -- where $old1 might be undefined. Is there any way to
> >> set a flag so that this just results in $old2 instead of
> >> the compiler throwing an error?
> >
> > Version 1 (much preferable):
> > $newVar = $old1 ? $old1 . $old2 : $old2;
> >
> > Version 2 (okay-ish):
> > $old1 ||= '';
> > $newVar = $old1 . $old2;
>
> What is ||="? Is that the same as
>
> $old1 = ($old1 || "");
Basically. Think of it as being in the group with += and *= ....
You can also use that structure for catenation with .=
Similarly (but not really the same), you can do here-docs like this:
my $here_doc =<<END;
this is all text going into the variable.
You can even embed $stuff as if it were double-quoted.
(but if you put any quotes around 'END' it acts as if
they were around the whole block.... and that 'END'
isn't a problem, because it has to me atthe start of
a line to count.
END
> What's the single double quote?
(in $old1 ||= '';)
That's just a false-but-defined empty string. Nothing magical.
> > Version 3 (ugly but workable):
> >
> > $newVar = ($old1||'') . $old2;
>
> Hmm.. I thought this was the prettiest one! =)
Then use that one, by all means! It's just a matter of taste.
Use what makes sense to you. =o)
> > Version 4 (requires lexical warnings):
> > { no warnings;
> > $newVar = $old1 . $old2;
> > }
> > Version 5 (ugh):
> > { local $^W = undef;
> > $newVar = $old1 . $old2;
> > }
> > *WHY* would you "rather not" check to see if it's defined first?
>
> I guess because I'm kind-of a purist when I shouldn't be.
I just meant that there has to be a test.
It doesn't have to use if/else keywords. :)
This is a complex if/then/else, but no keywords:
my $v = $x ? 1
: $y ? 2
: $z ? 3
: undef;
> Thanks for the tips.
> - Bryan
Any time. ;o]
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