Win a copy of Re-engineering Legacy Software this week in the Refactoring forum
or Docker in Action in the Agile forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

BigDecimal

 
Ashutosh Deo
Greenhorn
Posts: 10
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I have to retain the exact value of a Double and convert it into a string.

Double value = 105312453566.35363465;

I tried doing a toString() on the above Double value... but it returns me an output 1.0531245356635364E11



Hence I tried converting it into a BigDecimal format using the below code... so that I can retain the exact value..

BigDecimal newValue = new BigDecimal(value);
System.out.println("BigDecimal Value: " + newValue);

But the output which I get is like this :

BigDecimal Value: 105312453566.3536376953125

which is again not what I want.


How can I get the exact value?
 
Ulf Dittmer
Rancher
Pie
Posts: 42967
73
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
That number has 20 digits, and doubles simply do not have that much accuracy. Around 16 digits is the most number of accurate digits that's possible. See #20 in the http://faq.javaranch.com/java/JavaBeginnersFaq for some background information.

The solution to your problem is to use the BigDecimal(String) constructor. It retains all digits of its parameter.
 
Andre Brito
Ranch Hand
Posts: 95
Java Scala
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I agree with Ulf.
An another approach is to multiply the double value for a number (like 1000) that makes the double an int.
 
Ulf Dittmer
Rancher
Pie
Posts: 42967
73
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
An int has even less precision than a double (around 10 digits), and a long has around 19, so neither of those would work in this case.
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic