?
Solved

Converting String input to double using NumberFormat. Got error: java.lang.NumberFormatException: For input string: "154,216.48"

Posted on 2004-04-02
7
Medium Priority
?
2,713 Views
Last Modified: 2012-06-27
Hi I've got a input string ("154,216.48")  with: "," as separator which I should convert to a double

  public double calculateNAV()
  {
    double NAV=calculateMarketCap()/calculateTotalShares();
    double NAVFormmated;
    NumberFormat nf = NumberFormat.getNumberInstance();
    nf.setMaximumFractionDigits(2);
    nf.setMinimumFractionDigits(2);
    String formattedNAV = nf.format(NAV);
    NAVFormmated=Double.parseDouble(formattedNAV); //error!
    return NAVFormmated;
  }

java.lang.NumberFormatException: For input string: "154,216.48"
so, how can I convert this value to a double?
I know DecimalFormat with pattern should be able to fix it. But is that the best way to do it.

Indeed what I need is to convert a 12345.6789 to 12345.68. What's the best way to do it? Thanks.

0
Comment
Question by:marzbuzz
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
7 Comments
 
LVL 15

Expert Comment

by:JakobA
ID: 10746152
You can not reliably contain a value with 2 decimals in a double.  In the double the decimals are stored in binary format so the only decimals that van be stored precicely are those that you may get by dividing by 2.  1/2, 1/4, 1/8, 7/8.

Actually we have the same problem in the decimal system. The only presice fractions we can write are those that come from dividing by 2 or 5. any other fraction will require rounding to limit the number of decimals. 1/3 becomes 0.333333333333..., etc.

You desire for 2 digits suggest you are working with money. the easiest solution is to store them in a long (as cents) that way all calculations will be correct. Later when you write the number for people to read you write them as dollars (with 2 decimals) again.

regards JakobA
0
 

Author Comment

by:marzbuzz
ID: 10746268
Sounds interesting. But this is part of a homework. So I think it should be fine to lose some precision.
0
 
LVL 14

Accepted Solution

by:
Tommy Braas earned 90 total points
ID: 10746310
I think you've misunderstood the use and purpose of NumberFormat, however it is a creative way of the class cluster.

DecimalFormat nf = new DecimalFormat("#########.00");  // supports numbers up to 999,999,999.99
String formattedNAV = nf.format(NAV);
NAVFormmated=Double.parseDouble(formattedNAV); // no error!
return NAVFormmated;
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:marzbuzz
ID: 10746554
Thanks orangehead911. I guess you are right. Using NumberFormat is a wrong choice. Just not that familiar with DecimalFormat. I guess DecimalFormat class is the best way to deal with this kind of question.
0
 
LVL 30

Expert Comment

by:GrandSchtroumpf
ID: 10748159
>  In the double the decimals are stored in binary format.
It's much more complicated than that.
Doubles in java follow the IEEE 754 standard (composed of sign, exponent and mantissa):
http://www.trotek.ec-lyon.fr/~muller/cours/numeration/flp_ieee.html.en
0
 
LVL 14

Expert Comment

by:Tommy Braas
ID: 10750850
Glad I could help! :-)
0
 

Expert Comment

by:vinod_063
ID: 12704629
i want to convert string st="jan" to duoble

if i do Double.parseDouble(st);  // i am getting Numberformat exception
0

Featured Post

What does it mean to be "Always On"?

Is your cloud always on? With an Always On cloud you won't have to worry about downtime for maintenance or software application code updates, ensuring that your bottom line isn't affected.

Question has a verified solution.

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

Java Flight Recorder and Java Mission Control together create a complete tool chain to continuously collect low level and detailed runtime information enabling after-the-fact incident analysis. Java Flight Recorder is a profiling and event collectio…
Go is an acronym of golang, is a programming language developed Google in 2007. Go is a new language that is mostly in the C family, with significant input from Pascal/Modula/Oberon family. Hence Go arisen as low-level language with fast compilation…
Viewers learn how to read error messages and identify possible mistakes that could cause hours of frustration. Coding is as much about debugging your code as it is about writing it. Define Error Message: Line Numbers: Type of Error: Break Down…
Viewers will learn about if statements in Java and their use The if statement: The condition required to create an if statement: Variations of if statements: An example using if statements:
Suggested Courses
Course of the Month11 days, 1 hour left to enroll

770 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