K&B Doubt p783, Q4 __A_V_.length

[Robert Elbourn]

Hi

import static java.lang.System.*;
class _ {
static public void main(String... __A_V_) {
String $ = "";
for (int x=0;++x< __A_V_.length
$ += __A_V_[x];
out.println($);
}
}

invocation = java _ - A .

Output is A.

I thought it would be _-A. because it takes the args and plonks them into a String... iterates through these adding them to the string and spitting it out but I am clearly missing something here, is it to do with java syntax invocation that means the _ - do not reach the args method???

help very welcome, though I am sure I will figure it out eventually....

[camilo lopes]

Please note that the compilaador makes a parse ai provided that the declarac�es are valid. One _ is a valid statement, issue a lot of attention and he used the ability to vargs feature of java 5 in the statement of the main only to obstruct.

[Robert Elbourn]

are you saying that the "_ -" are dropped when parsing? or when copying into the String... ?

[Robert Elbourn]

also I have 1.6 running in Eclipse

I put into the arguements (so not exactly from the command line)
java _ - A .

and this came out

-A.

now I've just realised that _ is the class definition so that isn't an arguement , so why does the - not get put into the string?

[Robert Elbourn]

Ok I had to change the arguements from
_ - A .
to

- A . and it looks like its coming with A. as the answer suggested, the only conclusion I can come up with is that - is used as an arguement for the virtual machine and therefore ignored as an arguement like
java blah - d or something? am I correct can anyone verify?

[Robert Elbourn]

Think I have it figured now, the ++x is pre-incrementing so the first character gets dropped ie. the -

the problem is I am sure I thought a previous question was pre-incrementing and it wasn't so .. nevermind,

anyway thanks for the help guys! :roll: