A challenge

[wtd]

What did I do wrong in the following code?

code:

class Foo {    public int[] bar() {       /* code omitted */    } } class Baz {    private Foo f;    public Baz() {       f = new Foo();    }    public void qux() {       for (int i : f.bar()) {          System.out.println(i);       }    } }

[Dan]

Are we sposted to reply by posting or PMing you :p. Also are there sposted to be more then one thing wrong?

[wtd]

There is supposed to be one thing wrong. Or at least, I am looking for one thing specifically.

The code omitted is not the problem. Assume that it returns an array of ints via some mechanism that is irrelevant to the question.

Please post. First come, first serve.

[Dan]

Well i could be wrong but public qux() needs a return type in it's deftion or has to have void.

I don't think this is what you meant tho. I have not seen a for loop done like that so i am not shure if it would work, i shall look at it more latter.

[wtd]

Indeed, it is not what I had in mind.

The loop is a 1.5+ for-each loop.

[wtd]

For fun, in another language:

code:

class Foo {    public def bar: Array[Int] = /* Code omitted */ } class Baz {    private val f: Foo = new Foo    public def qux {       for (val i <- f.bar) println(i)    } }

[PaulButler]

I can't see anything that would prevent the code from compiling, is the mistake in the OOP design?

Should you have done the printing function inside the Foo class instead of the Baz class? Since you are printing the output of the Foo.bar method, it doesn't make sense to stick it in another class which is not used in the printing process.

[wtd]

No. Good thoughts, but you're not even close.

[OneOffDriveByPoster]

code:

public void qux() {       for (int i : f.bar()) {          System.out.println(i);       }    }

Call to f.bar() can return null. Do not know if that is what you are looking for though.

[wtd]

It is not.

[Aziz]

The classes should be public...

[Aziz]

And be in separate, properly named files. Though, again, perhaps not what you're looking for.

[OneOffDriveByPoster]

PaulButler @ Mon Jul 09, 2007 9:37 pm wrote:

Should you have done the printing function inside the Foo class instead of the Baz class? Since you are printing the output of the Foo.bar method, it doesn't make sense to stick it in another class which is not used in the printing process.

Maybe Baz should extend Foo instead of having a private Foo member?

[Aziz]

I think it's more of a logical/syntax error or even theory, as there is no clue to the business rules that would apply to this model. There could be an Baz object that contains a Foo, and uses the qux() method the print it's child's (a Foo) property that is returned from bar() (which happens to be an array of int)

[wtd]

Aziz is starting to think along the right lines.