BigDecimal don't understand, doesn't add up right

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epicwinter@hotmail.com - 31 Oct 2006 20:22 GMT

I don't understand how I am suppose to use the bigdecimal class. If i
do this:
BigDecimal total = new BigDecimal(0);
total.add(new BigDecimal(100));
total.add(new BigDecimal(112.222));
System.err.println("total: " +new Double(total.setScale(2,
java.math.BigDecimal.ROUND_HALF_UP).doubleValue()));

The output is zero. Why? Everytime you intialize the big decimal to
zero it won't function?

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Oliver Wong - 31 Oct 2006 20:32 GMT

>I don't understand how I am suppose to use the bigdecimal class. If i
> do this:
[quoted text clipped - 6 lines]
> The output is zero. Why? Everytime you intialize the big decimal to
> zero it won't function?

BigDecimal is immutable. When you do total.add(new BigDecimal(100)),
you're not changing the value. Rather, a new BigDecimal object is created
and returned, but you're throwing away this new object. You should write
your code as:

total = total.add(new BigDecimal(100));

for example.

- Oliver

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Mike Schilling - 31 Oct 2006 20:33 GMT

BigDecimals are immutable, like strings.

Try::

total = total.add(new BigDecimal(100));
etc.

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epicwinter@hotmail.com - 31 Oct 2006 20:41 GMT

banging head against wall...
thanks

> >I don't understand how I am suppose to use the bigdecimal class. If i
> > do this:
[quoted text clipped - 13 lines]
> total = total.add(new BigDecimal(100));
> etc.

Reply to this Message

BigDecimal don't understand, doesn't add up right

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