Solved

round up issues.

Posted on 2004-10-06
9
204 Views
Last Modified: 2010-04-01
Hi i am having some problem.
let say i have this value,

double amount = 1000;

if I divide this 1000 with 12, i will have 833.33333333333
so, what i do is i round it with 2 decimal point, to become 833.33

but when end of the day, i want to sum up all the 833.33, means 833.33 * 12, i will only get 9999.96, lost 0.04

How can i resovle this issues?? Can i use BigDecimal?? If yes, how can i apply the technique to sovle this issues?
0
Comment
Question by:chainreaction
  • 4
  • 3
9 Comments
 
LVL 35

Expert Comment

by:TimYates
ID: 12236343
Don't round it to 2dp...

Just display it as 2dp to the user, using java.text.DecimalFormat, but keep the number as 833.3333333333333333
0
 

Author Comment

by:chainreaction
ID: 12245018
but how many decimla point i should keep?

How many decimla point "double" and bigDecimal can handle?

Fiurther, this 8333.3333 is going to stored into the DB and in the data field, i onluy cater for 4 decimal.

What is the common solution for this?

Thank You.
0
 
LVL 35

Accepted Solution

by:
TimYates earned 250 total points
ID: 12246466
> i onluy cater for 4 decimal.

?

Why not assign the field type as DOUBLE, then it is a 64 bit floating point number, and you can just store the java double as it is into the databse...

> How many decimla point "double" and bigDecimal can handle?

It depends on the size of the integral part of the double, but it should be plenty for your application...

>  but how many decimla point i should keep?

All of them....save it in a double, never change it from a double and just display it to the user as a String...  But really it will be a double...
0
Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

 

Author Comment

by:chainreaction
ID: 12247121
OK. I am using Oracle, let say for example. in the table filed. if i choose the table field  type as Number, i will have to specified the "scale" of the Number. I have to decide what is the decimal point i should allow it to insert.

And if i am in Db2, i also need to specify the scale of the number data type.

Are we referring to the same things??
0
 
LVL 35

Expert Comment

by:TimYates
ID: 12248053
Why don't you define it as type "DOUBLE"?
0
 

Author Comment

by:chainreaction
ID: 12255364
in the database? Do we have the DOUBLE data type in databse??
0
 
LVL 35

Expert Comment

by:TimYates
ID: 12256814
yeah.  then you shouldn't need to round the double at all...
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you are looking at this article, you have most likely been hit by some version of ransomware and are trying to find out if there is anything you can do, or what way you should react - READ ON!
There's a lot of hype surrounding blockchain technology. Here's how it works and some of the novel ways it' s now being used - including for data protection.
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

840 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question