Re: Newbie: cloning a Number

Daniel Pitts wrote:
Philipp wrote:
Andreas Leitgeb wrote:
Philipp <sicsicsic@xxxxxxxxxxx> wrote:

My application needs some parameters (Number).
So, you could just as well use double or long.
Yes this is correct.
I just thought that this was the whole purpose of a "Number" class. ie
not needing to say if it's actually an integer or a double, but leaving
this to when real calculation is done.

Also my parameters are displayed in JFormattedTextFields which I would
like not to display Integers and Double the same way (with or witout
fraction digits). So keeping this info seemed important to me.

From my C++ background I would have implemented the standard math
operators (+ - * /) on Number such that the polymorphism is used (ie if
Number*Number is actually Integer*Integer: do integer math. If it's
Double*Integer do double math). But this does not seem to be the purpose
of the Number class in Java.
(what's it's purpose actually?)

Best regards
Phil
I believe the Number class's primary purpos is to provide a constant
way to represent numeric values as Objects in a type independant way.
All Number subclasses have intValue(), floatValue(), etc..., so that
you can convert from a Number object to any primative type.

Other than that, most people use a specific Number subclass, rather
than Number itself.


Unfortunately, they are not required to have a consistent conversion to
BigDecimal. That is the only API type that can exactly represent the
value of any double, any long, any BigInteger, etc., and provides
operations on them.

Patricia
.

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