«

Hello,

I was reading the chapter about vectors, and find out that every element is
an object. Why does each element have to be an object?

Also is there a program that shows the stack and heep as the program is
running?

Thanks

"Floppy" <> wrote in message
news:nuoQa.454100$. ca...
> Hello,
>
> I was reading the chapter about vectors, and find out that every element
is
> an object. Why does each element have to be an object?

Vectors are "flexible" arrays, holding varying numbers of elements. What the
vector actually stores is reference variables. Reference variables are used
to reference objects. Therefore, a vector stores "objects" in a loose sense.
In the technical sense every element of a vector is a reference.
Once you understand this, you see that your statement "every element is an
object" is wrong and leads to questions like the one you asked, which
doesn't make sense.
It's only a lazy way of thinking/speaking to say a vector "contains
objects." A vector (and all the collection framework structures) contain
references to objects.
--
Gary

Floppy:

>I was reading the chapter about vectors, and find out that every element is
>an object. Why does each element have to be an object?

Object is the base class of all classes in Java. Each class extends
Object, thus every object can be stored in a Vector. So there is no
restriction when it comes to classes, if that's what you meant.

On the other hand, no variables of primitive types like int, char or
float can be stored in a Vector. That _is_ a restriction, which will
be removed in Java 1.5.

>Also is there a program that shows the stack and heep as the program is
>running?

Many IDEs give you the opportunity to check a variable's content while
the program is being debugged. BTW, it's "heap" (just so you are more
successful with web searches).

Regards,
Marco
--
Please reply in the newsgroup, not by email!
Java programming tips: http://jiu.sourceforge.net/javatips.html
Other Java pages: http://www.geocities.com/marcoschmidt.geo/java.html

On Mon, 14 Jul 2003 02:23:15 GMT, "Floppy" <>
wrote or quoted :

>I was reading the chapter about vectors, and find out that every element is
>an object. Why does each element have to be an object?

The author could have written variants to contains ints, strings etc.

However, Object was the most general. It can hold int if you put it in
an Integer wrapper.

--
Canadian Mind Products, Roedy Green.
Coaching, problem solving, economical contract programming.
See http://mindprod.com/jgloss/jgloss.html for The Java Glossary.

"Floppy" <> wrote in message news:<nuoQa.454100$ .ca>...
> Hello,
>
> I was reading the chapter about vectors, and find out that every element is
> an object. Why does each element have to be an object?

Because of the way Java was designed. Primitive types are separated from objects.

> Also is there a program that shows the stack and heep as the program is
> running?

It's called a debugger. There are plenty of free ones.

/Jesper Nordenberg