easy debug question?

[Bruce Duncan]

I know this has to be easy, but I can't seem to figure it out. I'm debuggin' someone elses code...

x="hello";
+x+"world"

....and I don't get it! What does the "+x+"world" do? If I alert(x) the only thing that comes out is "hello". I also wondered why it doesn't error without the ";" at the end of the line.

I appreciate the help...

-Bruce Duncan
**** feeling dumb today...just wait till tomorrow....*** *

[kaeli]

Re: easy debug question?

In article <10b958im5clch4 f@corp.supernew s.com>,
bruce~w~duncan@ ~hotmail.com enlightened us with...[color=blue]
> I know this has to be easy, but I can't seem to figure it out. I'm debuggin' someone elses code...
>
> x="hello";
> +x+"world"
>
> ...and I don't get it! What does the "+x+"world" do?
> If I alert(x) the only thing that comes out is "hello".
> I also wondered why it doesn't error without the ";" at the end of the line.
>
> I appreciate the help...
>[/color]


Um, I don't think the semi-colon should be there. I think it was
supposed to be one line. Or the second line should have been
x=x+" world";
That code doesn't look like it is valid. Note that browsers don't
necessarily show you errors.

Semi-colons are not required at the end of the line in JS; they are
recommended for clarity if the end of the line is also the end of the
statement.
(the above is a bit simplified)

--
--
~kaeli~
You feel stuck with your debt if you can't budge it.

http://www.ipwebdesign.net/wildAtHeart

http://www.ipwebdesign.net/kaelisSpace

[Bruce Duncan]

Re: easy debug question?

"kaeli" <tiny_one@NOSPA M.comcast.net> wrote in message
news:MPG.1b1e60 14bdaf3d25989e9 4@nntp.lucent.c om...[color=blue]
> In article <10b958im5clch4 f@corp.supernew s.com>,
> bruce~w~duncan@ ~hotmail.com enlightened us with...[color=green]
> > I know this has to be easy, but I can't seem to figure it out. I'm[/color][/color]
debuggin' someone elses code...[color=blue][color=green]
> >
> > x="hello";
> > +x+"world"
> >
> > ...and I don't get it! What does the "+x+"world" do?
> > If I alert(x) the only thing that comes out is "hello".
> > I also wondered why it doesn't error without the ";" at the end of the[/color][/color]
line.[color=blue][color=green]
> >
> > I appreciate the help...
> >[/color]
>
>
> Um, I don't think the semi-colon should be there. I think it was
> supposed to be one line. Or the second line should have been
> x=x+" world";
> That code doesn't look like it is valid. Note that browsers don't
> necessarily show you errors.
>
> Semi-colons are not required at the end of the line in JS; they are
> recommended for clarity if the end of the line is also the end of the
> statement.
> (the above is a bit simplified)
>
> --
> --
> ~kaeli~
> You feel stuck with your debt if you can't budge it.
> http://www.ipwebdesign.net/wildAtHeart
> http://www.ipwebdesign.net/kaelisSpace[/color]

I believe you are correct Kaeli!
I was hoping that it wasn't some wierd way of assigning vars that I just
hadn't seen before. My mind isn't working so great this morning...thank s
for the response...it helped open my eyes a bit.

-Bruce Duncan

[Grant Wagner]

Re: easy debug question?

Bruce Duncan wrote:
[color=blue]
> I know this has to be easy, but I can't seem to figure it out.
> I'm debuggin' someone elses code... x="hello";
> +x+"world"...an d I don't get it! What does the "+x+"world"
> do? If I alert(x) the only thing that comes out is "hello". I
> also wondered why it doesn't error without the ";" at the end
> of the line. I appreciate the help... -Bruce Duncan**** feeling
> dumb today...just wait till tomorrow....*** *[/color]

The +x + "world" doesn't do anything. Well, actually, it applies
the unary operator to the value of x (returning zero). toString()
is implicitly called on that zero and it is concatentated to the
word "world". The result is a string "0world". However, that
value is never assigned to anything, so it is discarded almost
immediately.

Semi-colons are only required in Javascript when multiple
statements appear on the same line, however, it's a good habit to
put them at the end of every non-block.

As for why this isn't doing what you want, I think what you want
is:

var x = "hello";
x = x + " world"; // notice x + " world" is assigned back to x
// you can also use x += " world";
alert(x);

--
| Grant Wagner <gwagner@agrico reunited.com>

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