Formatting a Double to 2 decimal places without first converting to String

Hi,
Does anyone have any clear idea on how to format a Double directly without first converting it
to a String.I have just read through DecimalFormat/NumberFormat but I think there might be an easier way.I am also aware of printf(%f) and format(%f),but unfortunately am using Java 1.4 at the moment which does not seem to support them(will upgrade soon).The code I have is as follows:
public void displayAnalysis ()
       System.out.println ("========================================================================");
       System.out.println ("========================================================================");
       System.out.println ("\nANALYSIS RESULTS FOR FILE " + inputFile + " \n");
       System.out.println ("========================================================================");
       System.out.println ("========================================================================");
       System.out.println ("\nString length: "+ inputText.length());
       System.out.println ("Ratio of printing to non-printing characters: "+ pRatio);
       System.out.println ("Ratio of vowels to consonants: "+ vRatio);
       System.out.println ("");
       System.out.println ("Frequency of vowels as a percentage of number of printing characters;");
       System.out.println ("Percentage of a's ="+ (NumberFormat.format(new DecimalFormat(((double)frequency[0]*100)/printable)))));
       System.out.println ("Percentage of e's ="+ ((double)frequency[1]*100)/printable + "%");
       System.out.println ("Percentage of i's ="+ ((double)frequency[2]*100)/printable + "%");
       System.out.println ("Percentage of o's ="+ ((double)frequency[3]*100)/printable + "%");
       System.out.println ("Percentage of u's ="+ ((double)frequency[4]*100)/printable + "%");
       System.out.println ("Number of whitespace characters were " + whitespace);
       System.out.println ("");
       System.out.println ("========================================================================");
       System.out.println ("========================================================================");
       System.out.println ("");
       System.out.println ("");
   }I would like to display the frequencies to 2 decimal places.As a last resort I will have to alter the code to use DecimalFormat,but I'm hoping someone has a simpler solution.

Oops,please ignore the line for the first frequency (a's),I was just playing around with trying to use NumberFormat!

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Rounding to 2 decimal places WITHOUT using any formatting class

Hello
I'm trying to round a number (double) to 2 decimal places without using any of the formatting class like (DecimalFormat or Math.Round and BigDecimal). Is it possible to do it by just using typecast?

OP:
BigDecimal is not a formatting class. Math.round isn't a class at all.
Typecasting doesn't really do that sort of thing at all (unless you count dropping fractional components when casting to an integer type).
double holds values in binary format, so it's basically impossible to round to decimal values meaningfully.
Chuck:
I thought that BigDecimal supported arbitrary decimal precision, so one doesn't have to do that sort of thing....?

Double value truncated to two decimal places without rounding the value.

I want to truncate double value to two decimal places without doing the rounding of the value.
Is there any method which can directly do the truncation.

There's many ways to achieve this such as using
BigDecimal's setScale method or type-casting. This is
the way I like to do it:double d = -5.239;
d = d > 0 ? Math.floor(d * 100) / 100.0 : Math.ceil(d
* 100) / 100.0;
Your division by 100 may cause an rounding error, because there are numbers which no finite binary representation. That's splitting hairs! I know ;-)

Rounding Doubles to Two Decimal Places

Hi All,
I've searched the archive and found a few different posts regarding restricting the number of decimal places in doubles. However they all suggest different methods, BigDecimal, NumberFormat etc.
Which is the simplest method of rounding a number say 10.023445656 to 10.02?
I tried using the java.text.NumberFormat but this turns the double into a string and I need the end result to be a double.
Thanks

Hi All,
I've searched the archive and found a few different
posts regarding restricting the number of decimal
places in doubles. However they all suggest different
methods, BigDecimal, NumberFormat etc.
Which is the simplest method of rounding a number say
10.023445656 to 10.02?
I tried using the java.text.NumberFormat but this
turns the double into a string and I need the end
result to be a double.
ThanksI ahve a small code that can do the work for u:
import java.text.*;
double format(double val, int dec){
    double multiple=Math.pow(10,dec);
    val=Math.round(val*multiple)/multiple;
    DecimalFormat df=new DecimalFormat("0.00");
    String format=df.format(val);
   double dval=Double.parseDouble(format);
   return dval;
}//end of functionHope that helps!

Print Doubles to two decimal places?

When I do calculations on my double numbers and then print them on screen I get a string of digits after the decimal point. Can anyone give me the code as to how I use the DecimalFormat class to make these digits print to 2 decimal places. I am sure it is very simple line or two of code but I am unsure how.
Thanks

double number = 123456.789;
DecimalFormat df = new DecimalFormat("#,##0.00");
System.out.println(df.format(number));
DesQuite

A double with 2 decimal places

I need to output a double that has 2 decimal places. The default is just one and I don't know the command to make it two. For example,i want an output of 37.5 to be displayed as 37.50. If you know the command, please tell me. Thanks!

Looks like you are trying to deal with money.
Firstly if you are dealing with money store everything as the lowest form of currency in your given area. eg as pence or cents and place it in a int or long. That way you dont get any rounding erros when you multiply up the value.
To put two decimal places on a number is easy just use a DecimalFormat from java.text
Like this
double myNumber = 3.1;
DecimalFormat decF = new DecimalFormat( "######0.00" );
String myFormattedNumber = decF.format( myNumber );
System.out.print( "My number is " + myFormattedNumber ); The #######0.00 in the DecimalFormat constructor call is a pattern that is used to format the number. The # indicate an optional number the 0 indicates a required number and if one is not provided a 0 will be included.

Double to 2 decimal places

I am putting a double variable out to a web page and also calculations on that double(a price). I am getting 4 decimal places on the original price and several decimal places on the calculations. Can anyone tell me how to round down to 2 decimal places?
Thank you.
Karen

I generally use a formatter along the lines of the following. You could also use a wrapper class (Double is final, and you can't extend primitives) for Double which would incorperate this formatting. However you only need to use it when you are presenting it (or if you are persisting it to a lower precision data source, where truncation could result in larger inaccuracies creeping in).
This also changes the ROUND_HALF_EVEN behaviour of DecimalFormat to ROUND_HALF_UP.
Alternatively you could use BigDecimal (.setScale() to set decimal places) but there is an overhead which may be restrictive.
class Formatter {
public static final int DEFAULT_PRECISION = 2;
public static final String DEFAULT_PATTERN = "#.00";
public static final String ZEROS = "0000000000000000";
public static String convertDoubleToString(Double d) {
    return convertDoubleToString(round(d, DEFAULT_PRECISION), DEFAULT_PATTERN);
public static String convertDoubleToString(double d) {
    return convertDoubleToString(round(d, DEFAULT_PRECISION), DEFAULT_PATTERN);
public static String convertDoubleToString(Double d, int precision) {
    return convertDoubleToString(round(d, precision), "#." + ZEROS.substring(precision));
public static String convertDoubleToString(double d, int precision) {
    return convertDoubleToString(round(d, precision), "#." + ZEROS.substring(precision));
public static String convertDoubleToString(Double d, String pattern) {
    return new DecimalFormat(pattern).format(d.doubleValue());
public static String convertDoubleToString(double d, String pattern) {
    return new DecimalFormat(pattern).format(d);
private static final double round(Double d, int precision) {
    double factor = Math.pow(10, precision);
    return Math.round((d.doubleValue() * factor)) / factor;
private static final double round(double d, int precision) {
    double factor = Math.pow(10, precision);
    return Math.round((d * factor)) / factor;
}

Formatting Numeric Only with Variable Decimal Places

Acrobat Pro 9, Windows XP
I'm creating a form that has a number of text box form fields that are to be numeric only per the form requestor. However, for any given field of this type the number of decimal places that can be entered can vary from 0-3 and the requestor does NOT want any unnecessary decimals to appear in the final output (e.g., a "1.2" entry should not appear as "1.200"). The standard number formatting properties always show all the decimal places so I know it's not that route. No calculations will be performed with any of these entries -- the form requestor merely is entering data and then printing it out so that it's legible for the end-user.
I know that the following line of JavaScript in the Custom Keystroke property limits the entry to numeric only, but how should I tweak the syntax to allow a decimal entry:
event.rc = (!event.change || /^\d$/.test(event.change))
I probably also need a script to format for decimal places, but I don't know where to look in the JavaScript for Acrobat API Reference or in the MDN JavaScript Reference.
Thanks in advance for any assistance.

Good question. To keep it simple (because there are about 300 form fields in this document), if they choose to add extra decimal zeros, then who am I to argue with their entry. So in your example for a given form field, if they enter "1.200" then I expect that they want "1.200" to display.
OK, but earlier you said:
"However, for any given field of this type the number of decimal places that can be entered can vary from 0-3 and the requestor does NOT want any unnecessary decimals to appear in the final output (e.g., a "1.2" entry should not appear as "1.200")."
This seems inconsistent. Can you clarify? The point is the code and where it's placed depends on this. It could be implemented either as a custom Validate or Format script, in addition to a Keystroke script.

Round off Double to 2 decimal places??

Hi all the pro out there..
anybody can tell me how to go about rounding off eg 5.9542 to 2 decimal places in java? i went to search in API Double class, no method that allow me to do that..
is there any other way?
pls advise thank you

If the former, you can do it manually by multiplying by an appropriate number, casting to int, and then dividing by the same number.Although this won't always work.
Suppose you want 1.125 --> 1.1
1.125 --> 11.25 --> 11 --> 1.1 plus some epsilon, since 1.1 can't be represented exactly in base-2.Yes, I know that (I assume you knew I knew that). So, maybe the OP needs to use both methods in combination (and maybe use some rounding method [such as in the Math class] other than cast).

Formatting amount to 2 decimal places without rounding the value

Hi
My requirement is to format the amount field, when I am using the simple type and setting the format as ###,##0.00 then it is rounding off the value. Foe example say the amount is 3,567.236 in this case it rounds it off to 3,567.24 which I do not want we want the value to display as 3,567.23. Does anyone have any idea how this can be achieved.
Thank you
Regards,
Preet

Use the following :
BigDecimal bigDecimalh = new BigDecimal("22.335642");
bigDecimalh = bigDecimalh.setScale(2, BigDecimal.ROUND_DOWN);
Regards,
Himanshu

Rounding up doubles to 2 decimal places

I'm currently rounding up a double in my program using Math.round(double)
However I want to strip any trailing zeros from the output, so:
1.235 would round to 1.24
but 1.00 would round to 1
How would I go about doing this?

Also I'm making my own function to round the doubles,
and they are returning doubles so I cannot return a
string.If they are returning doubles that the number of "trailing zeros" is irrelevant, as that is formating. Really you should keep the precision until you want to display it, then use the formatter above.
What are you doing?
I'm going to take a shot in the dark; has this got something to do with money?

Formatting currencies and decimal places

I'm currently using NumberFormat.getCurrencyInstance() to format numbers as currency. However, one problem I'm having is that I'd like values with no cents to be formatted with no decimal places, and any values with cents to be formatted with the usual 2 decimal places. For example:
17 would be formatted as $17
17.45 would be formatted as $17.45
17.4 would be formatted as $17.40
The last one is the tricky part--I've tried formatter.setMinimumFractionDigits(0), and this works great for the first two cases. But for the last case, the number gets formatted as $17.4.
Basically my problem is I want a number to be formatted with zero or two decimal places and nothing in between. Is there an easy way to do this?
Thanks in advance.

Otherwise you are likely to find that you are getting .00 due to errors from previous calculations. You are right. Adjusted it to Locale aware
import java.text.FieldPosition;
import java.text.NumberFormat;
import java.text.ParseException;
import java.text.ParsePosition;
import java.util.Locale;
public class SpecialCurrencyFormat extends NumberFormat {
    private static final long serialVersionUID = 1L;
    private final NumberFormat noDecimals;
    private final NumberFormat decimals;
    private final double maxDifference;
    private final double factor;
    public SpecialCurrencyFormat() {
     this(Locale.getDefault());
    public SpecialCurrencyFormat(Locale locale) {
     decimals = NumberFormat.getCurrencyInstance(locale);
     noDecimals = NumberFormat.getCurrencyInstance(locale);
     noDecimals.setMaximumFractionDigits(0);
     maxDifference = Math.pow(10, -decimals.getMaximumFractionDigits()) * .5;
     factor = Math.pow(10, decimals.getMaximumFractionDigits());
    @Override
    public StringBuffer format(double number, StringBuffer toAppendTo,
         FieldPosition pos) {
     double adjustedValue = (Math.round(number * factor)) / factor;
     if ((Math.abs(number - Math.round(number)) < maxDifference)) {
         return noDecimals.format(adjustedValue, toAppendTo, pos);
     } else {
         return decimals.format(adjustedValue, toAppendTo, pos);
    @Override
    public StringBuffer format(long number, StringBuffer toAppendTo,
         FieldPosition pos) {
     return noDecimals.format(number, toAppendTo, pos);
    @Override
    public Number parse(String source, ParsePosition parsePosition) {
     return decimals.parse(source, parsePosition);
    public static void main(String[] args) {
     NumberFormat nf = new SpecialCurrencyFormat(Locale.US);
     double[] values = { 10000, 1000, 100, 10, 1, 10.1, 10.01, 10.001,
          10.002, 10.003, 10.004, 10.005, 10.006, 10.007, 10.008, 10.009,
          10.010 };
     for (double value : values) {
         print(nf, value);
    private static void print(NumberFormat nf, double number) {
     String formatted = nf.format(number);
     try {
         System.out.println(number + "\tas " + formatted + "\tand back "
              + nf.parse(formatted));
     } catch (ParseException e) {
         e.printStackTrace();
}The value adjustedValue is needed since NumberFormat doesn't seem to round the value. It just breaks.
Piet

How to change a double to 2 or less decimal places

hi
im trying to change a double to 2 decimal places
the reason is i have a angle that is sesitive to 1.0 x14
and it look rediculas to look at :)
i think on a calculater you use E exponents
but im unsure.

There's a DecimalFormat class. And also Formattable interface. Classes implenting the latter can be formatted using a Formatter which employs the notation common in C and other languages.
String has a format() method that allows a formatted string to be produced, and there are numerous printf() methods in PrintWriter, Console etc
public class RoundingEg {
    public static void main(String[] args) {
        double pi = Math.PI;
            // %.2f means "floating point number with 2 dp"
            // %n means "ewline"
        System.out.printf("%.2f%n", pi);
            // or to obtain a string
        String displayStr = String.format("%.2f", pi);
        System.out.println("Used as any other string: " + displayStr);
}

Number formatting with either 2 decimal places or none

Hello,
I'm using Acrobat 8 in XP and not familiar with Javascript.
I have some dollar amount fields where I need it to be number formatted, and limited to 2 decimal places but leave the user the ability to enter only an integer.
ie, go to two decimal places if any of
> .
> .0
> .00
> .000(...)
are present but leave it off if none are present.
I assume I need a custom format script but I've not been able to learn enough to figure it out yet.
If anyone can give me some code I can edit and paste, that would be great. Any help is appreciated.

> Have a String as "3.0000000"
String s = "3.0000000";
System.out.printf("%.2f", Double.parseDouble(s)); // 3.00
Formatting - Numbers and Currencies
~

Without to change the setting.how to set the decimal place to 7 for an UDF.

Without to change the setting, how to set the decimal place to 7 for an UDF?

Hi
Once you create a UDF it will automatically be binded to the data source of data type that you gave at the time of creating UDF.
So i think you can not set the decimal places without changing the setting in display parameters.
i am not sure whether it will work or not one thing you can try is that create it as a alphanumeric data type and convert your decimal value to sting and then assign it to UDF,While retrieving for any manipulation you convert it as decimal.
Hope it helps you
Regards
Vishnu

Formatting a Double to 2 decimal places without first converting to String

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