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
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
2,702 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
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 30 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
Free Tool: Port Scanner

Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.

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.

 

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

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

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

Suggested Solutions

Title # Comments Views Activity
V.simple question about Android packages and libraries 1 29
table example 4 32
HashTable highest marks enumeration alternative 9 43
servlet example 17 51
For customizing the look of your lightweight component and making it look lucid like it was made of glass. Or: how to make your component more Apple-ish ;) This tip assumes your component to be of rectangular shape and completely opaque. (COD…
Introduction This article is the last of three articles that explain why and how the Experts Exchange QA Team does test automation for our web site. This article covers our test design approach and then goes through a simple test case example, how …
Viewers will learn about basic arrays, how to declare them, and how to use them. Introduction and definition: Declare an array and cover the syntax of declaring them: Initialize every index in the created array: Example/Features of a basic arr…
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.

839 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