# place « decimal « Java Data Type Q&A

### 1. How to round a number to n decimal places in Java    stackoverflow.com

What I'd like is a method to convert a double to a string which rounds using the half-up method. I.e. if the decimal to be rounded is a 5, it always ...

### 2. How to check if a double has at most n decimal places?    stackoverflow.com

Currently i have this method:

``````static boolean checkDecimalPlaces(double d, int decimalPlaces){
if (d==0) return true;

double multiplier = Math.pow(10, decimalPlaces);
double check ...``````

### 3. Java: Check if two double values match on specific no of decimal places    stackoverflow.com

Comparing those two values shall result in a "true":

``````53.9173333333333  53.9173
``````

### 4. How many decimal Places in A Double (Java)    stackoverflow.com

All, Is there any in built function in java to tell me how many decimal places in a double. For example: 101.13 = 2 101.130 = 3 1.100 = 3 1.1 = 1 -3.2322 = 4 ...

### 5. Rounding off a double to 3 digit decimal place but zero at 3rd decimal place disappears in java    stackoverflow.com

I want to round of my double to 3 decimal places in java. I don't want to trim off the zero. So if my double is 2.34, I still want it ...

### 6. How do you generate a random number with decimal places    stackoverflow.com

``````I would like to generate random numbers between 1 & 10, with a decimal place of 1
(e.g. 1.5, 9.4, 6.3, 2.9)

I would like to generate random numbers between 1 & ...``````

### 7. Moving decimal places over in a double    stackoverflow.com

So I have a double set to equal 1234, I want to move a decimal place over to make it 12.34 So to do this I multiply .1 to 1234 two times, ...

### 8. round double to two decimal places in java    stackoverflow.com

ok this is what I did to round a double to 2 decimal places,

``````amount = roundTwoDecimals(amount);

public double roundTwoDecimals(double d) {
DecimalFormat twoDForm = new DecimalFormat("#.##");
...``````

### 9. Rounding to 2 decimal places    stackoverflow.com

``````(Math.round(doubleValue*100))/100.0
``````
Is there a better way to round decimals to 2 decimal places?

### 10. Using double up to two decimal places    stackoverflow.com

I want to use double up to just 2 decimal places. i.e. it will be stored upto 2 decimal places, if two double values are compared then the comparison should be ...

### 11. DecimalFormat decimal places    stackoverflow.com

Currently, I have BigDecimal values with 3 decimal places shown in a JTable. When i get values as 2.500 or 1.000, I want to have 2.5 and 1.0 instead. That's why ...

### 12. Java: Getting time with currentTimeMillis() as a long, how do I output it with X decimal place accuracy?    stackoverflow.com

I have a long that represents System.currentTimeMillis(). I then took another measurement of the time into a long var later in my code. I subtracted the two but now want to ...

### 13. How can I truncate a double to only two decimal places in Java?    stackoverflow.com

For example I have the variable 3.545555555, which I would want to truncate to just 3.54.

### 14. How to display a number with many decimal places? (Java)    stackoverflow.com

I was wondering if there is a way to "cheat" and work with numbers with way more decimal places than a double in Java, and then display it via `[Graphics Object].drawString(number, ...`

### 15. Rounding float/decimal to 3 decimal places exactly?    stackoverflow.com

I know there are many questions asking for this, but I have tried quite a few of the solutions but none seem to work exactly how I need it! Most solutions work, ...

### 16. Trim Double to 2 decimal places    stackoverflow.com

should be an easy one. I originally was gonna do this in javascript but have to do it prior to setting to the form in my handler page. Anyway ...

### 20. trying to restrict decimal places in double    coderanch.com

Hi Just a quick one. Anyone know how to restrict the number of decimal places in a doouble value to 2? I've had a look around and seen a few answer with silly caluculations (divide by 100 * by itself etc...) but none of them seem to work. All i want to do is reduce the decimal places for a value ...

### 21. String to double losing decimal places    coderanch.com

Why does the following occur? A double can hold these numbers can't it? source = "1234567890123.1234"; dvalue = Double.parseDouble(source); result = formatter.format(dvalue); out.print(source + " = " + result + br); //gives1234567890123.1234 = 1,234,567,890,123.1233 source = "12345678901234.1234"; dvalue = Double.parseDouble(source); result = formatter.format(dvalue); out.print(source + " = " + result + br); //gives12345678901234.1234 = 12,345,678,901,234.123 source = "123456789012345.1234"; dvalue = Double.parseDouble(source); ...

### 22. Decimal Place Problem    coderanch.com

Hi guys, I can't get the right decimal format to print on my screen. Here's an example. Zoom Percentage: 9/128 = 0.0 Zoom Percentage: 7/26 = 0.0 Zoom Percentage: 5/26 = 0.0 Zoom Percentage: 7/19 = 0.0 Zoom Percentage: 2/19 = 0.0 Zoom Percentage: 3/18 = 0.0 Zoom Percentage: 2/18 = 0.0 Zoom Percentage: 1/14 = 0.0 Zoom Percentage: 2/14 = ...

### 26. 2 decimal places    coderanch.com

How can I guarantee that a double result will always be in the 2 decimal places format? I've noticed that using double actually distorts the real result. For example : 15.62 - 10 = 5.619999999 (or something like that). I want it to equal 5.62 as any normal person would. Any help???

### 28. How to restrict the decimal place of a floating point number?    coderanch.com

Hi, Here is my code: public void TwoDecimal(double u){ String w = Double.toString(u); int c = w.length(); System.out.println(c); if (c <= 5) { double a = Double.parseDouble(w); System.out.println(a); } else { System.out.println("Invalid input!"); } } I want to show a floating point number which has 2 digits and 2 decimal places, e.g. 45.82, 29.67. This number is input by user and ...

### 29. Method for limiting decimal places?    coderanch.com

I'm using the double type within an equation and printing out the results. However, depending on the double types used within the equation, I can end up with several places to the right of the decimal point. Is there a method that will limit the number places to the right of a decimal point? Thanks for your time,

### 30. Only 2 decimal places!!!!    coderanch.com

Thanks for the help, but im very new to java and im not too sure where the code goes for the decimal format...? import javax.swing.JOptionPane; public class Assignment1 { public static void main(String[] args) { // calls method start(); } public static void start(){ // declares all the vars... String choice1, choice9, choice2, choice3, choice; int one, two, three, tot1, tot2, ...

### 31. Rounding Doubles to Two Decimal Places    coderanch.com

Since you are using JUnit, there is no reason to round. Instead, you should use Assert.assertEquals(double expected, double actual, double precision) to compare the two numbers. The last parameter indicates the accuracy of your comparison. For example, you can do something like Assert.assertEquals(manualValue, calculatedValue, 0.01) To assert that your calculated value is within 1/100 th of the manually derived value. For ...

### 33. Number of decimal places?    coderanch.com

I want to write a function which returns the number of decimal places a given number has (double). It sort of works... but not 100%. Here is what i have so far: //return an integer stating how many decimal points the number has //assume the number provided is a positive double private static int getNumberOfDecimals(double number){ //convert the number to a ...

### 35. Rounding to decimal places.    coderanch.com

hi jon, i can't contribute to the DecimalFormat question, but if you only need to do this conversion a few times, it might not be worth the creation of an additional object. in this case, i would prefer a hand-made code, e.g. double fact = Math.pow(10, nDigits); double rounded = Math.round(x*fact) / fact; nDigits is the decimal place you want to ...

### 37. How do i round a double to two decimal places?    coderanch.com

I've tried a couple of math formula's, and using java.text.decimalformatter buut, I'm not having much luck. I need something that not only works for decimals with a large amount of numbers after the decimal point. But also something that works for converting an int 30, to double 30.0 and than gives me 30.00...if possible. Is it?

### 38. Decimal Places    coderanch.com

I hope someone can lead me in the right direction. I am trying to format my currency to two decimal places, for instance, whenever I enter an amount like 75.50 is shows up as 75.5. Also whenever the program computes the change is comes out as 3.0900000034. Here is an example of the output I get Enter amount of purchase: 98.00 ...

### 39. Limiting decimal places in a double    java-forums.org

Agree. Avoid RoseIndia unless you want advice that may or may not be correct. The question I would like to ask is this: do you truly want to round the number or the display of numbers? Often what matters is the latter, and if that is your case, then you may wish to look into the String.format/Formatter/printf family or DecimalFormat. Edit: ...

### 41. 3 Decimal Places    java-forums.org

You're going to need to show more information, as I don't know where those numbers at the bottom are coming from, or really what you are trying to do. Maybe post what your test data is or better yet your test class. In your setHoursWorked(int, int) make sure you either typecast the min variable to a double or the 60 to ...

### 46. decimal places and colors    forums.oracle.com

Also, im not sure this technically counts as a "java" question, but im trying to do it in my java program so ... i'll ask anyway and hope its not too inappropriate. Im trying to use the Color class to specify an RGB value thats somehow based off of another value in my objects. I have a number between 0 and ...

### 49. Round decimal number to two places    forums.oracle.com

trying to round a decimal number to two places i.e. 1.98999 should round to 1.99. -tried using math.round but it only rounds to nearest integer -tried using decimalformat class but that converts to string, and cast wont allow me to convert from string back to double *is there a round method that allows you to specify decimal places? *or is there ...

### 50. Two decimal places    forums.oracle.com

public class RoundTwoDecimalPlaces{ public static void main(String[] args) { float num = 2.954165f; float round = Round(num,2); System.out.println("Rounded data: " + round); } public static float Round(float Rval, int Rpl) { float p = (float)Math.pow(10,Rpl); Rval = Rval * p; float tmp = Math.round(Rval); return (float)tmp/p; } } Edited by: javaboy on Nov 11, 2007 12:46 PM

### 56. Rounding up doubles to 2 decimal places    forums.oracle.com

Nope, nothing to do with money, however my rounding method uses Math.round(100*x) and then divides by 100 to get the output. I reason I want to get rid of the zeros is because it is part of an assignment that states that we ned to get rid of any trailing zeros. I tried using the format method but i couldn't work ...

### 57. Rounding up doubles to 2 decimal places    forums.oracle.com

Hi i have written a simple project to convert currency which is working fine but i am struggling to figure out how to round the outputs to two decimal places. E.g. 1.563434 would equal 1.56. Here is the program i have written but i do not know where to add the math instruction or which to use as there seems to ...

### 59. How to write an average to one decimal place and make it round up.    forums.oracle.com

Got him angry. There you go Djaunl. I can always count on you warnerja. @MoMo: How do you expect to get help when you insult people? How do you expect to get help when you cannot communicate? How do you expect to get help when someone on the internet launches you into a rage-filled tirade? Why are you taking a class ...

### 60. decimal places    forums.oracle.com

if i do that the calculations are all wrong. so what did i mess up? Not knowing what "all wrong" means how can I know. The line W=(H*H)/28; says square H then divide by 28 before converting to a double. The division is done in integer so all decimal places are lost. You could change this to W=(H*H)/28.0 but this will ...

### 61. rounding numbers to 2 decimal places    forums.oracle.com

i thought that my equation would be causing a problem and that i might need to do a cast -- I relized that this is not the problem for the type of string i am using the ("0.00") After trying various things the string does work if im just outputing it to the screen but i also use this rounding in ...

### 62. New question....adding decimal places...    forums.oracle.com

There is a 10.00% tax on the total order amount. Write a Java program that reads the number of each type package on an order and computes the cost for the packages of each type ordered. Total the order, calculate the tax on the order, and the total including the tax. Print all items read and all items calculated with appropriate ...

### 66. Excel and Java Decimal Place Precision    forums.oracle.com

Excel and Java shows decimal places differently. For example if I square 19.0626, the last three digits is not the same. Java - 363.3833508 Excel - 363.3833539 Is there a way to fix this? I want the number to follow the Excel precision This is how I produce the number - sqrtAverage = (average - Double.parseDouble(input.get(i))) * (average - Double.parseDouble(input.get(i)));

### 67. Three decimal places in my calculation    forums.oracle.com

Hi, I have a division calculation, a/b where both a and b are int's. now when i want the result upto 3 decimal places. i have done this. Double d = a/b; DecimalFormat c = new DecimalFormat("0.###"); c.format(d); System.out.println(d); Still I am unable to get 3 decimal places. I want 3 decimal places even for a 0 value like 0.000. Thanks. ...

### 69. how do i round a double to 2 decimal places    forums.oracle.com

Do you mean you want to round the result to 2 decimal places, or you want to display it to 2 decimal places? If the latter, then yes, DecimalFormat is the place to look. If you actually want to truncate the value and use it later, I would suggest either using BigDecimal, or using integers and multiplying by 100. Then divide ...

### 72. help on limiting decimal places    forums.oracle.com

Hi I have set up some code which increments.When i inspect it as it is incrementing it can go from 4....4.900009 etc.... and i was wondering if there was a way how i can limit how many decimal place it can take up.It would be helpful if it was 2 dp.Could anyone give some help and please may you give an ...

### 73. help wanting to limit output to 2 decimal places :O    forums.oracle.com

public class Main { public static void main(String[] args) { double Hours_Worked, Hourly_Wage, Total_Money; final double COMMISSION = 3.59 * .1; int noSoldFish; String UserName; System.out.println("Please enter the employee's name: "); UserName = Keyboard.readString(); System.out.println("Please enter hours worked by employee: "); Hours_Worked = Keyboard.readDouble(); System.out.println("Enter employee's hourly wage: \$"); Hourly_Wage = Keyboard.readDouble(); System.out.println("Enter the number of fish sold by employee:"); noSoldFish ...

### 76. round decimal to two places    forums.oracle.com

trying to round a decimal number to two places i.e. 1.98999 should round to 1.99. -tried using math.round but it only rounds to nearest integer -tried using decimalformat class but that converts to string, and cast wont allow me to convert from string back to double *is there a round method that allows you to specify decimal places? *or is there ...

### 81. Round a double value to a specific number of decimal places?    forums.oracle.com

No, because doubles hold values in binary (as do all values in a computer, of course, but there's no additional stuff to indicate decimal values). If you want values with specific rounding rules in decimal, use java.math.BigDecimal. If you just want to format the number with a specified number of decimal digits, use java.text.DecimalNumber.

### 82. Two decimal places    forums.oracle.com

Hi I am trying to convert a double number to two decimal places. Even if a number ends up as being 1.3, I want to convert it to 1.30 instead. I am using the DecimalFormat method and I got the following code for it: concessionField.setText("No"); String cf2 = priceField.getText(); double cfd2 = Double.parseDouble(cf2); cfd2 = cfd2 * 2; DecimalFormat df2 = ...

### 83. How to find decimal place?    forums.oracle.com

If I have a number such as: 123.45 how can I figure out that the number has a decimal point greater then 0? I just want to isolate the decimal part and compare it's value, but I'm not sure what a good way to do that would be. My first thought was to change it to a string and then back ...

### 84. How to take float precision to two decimal places?    forums.oracle.com

String strQuartes, strDimes, strNickels, strPennies; int intQuartes, intDimes, intNickels, intPennies; float fltValue; BufferedReader dataIn = new BufferedReader(new InputStreamReader(System.in)); System.out.println("THE COIN CALCULATOR"); System.out.println(); System.out.print("Enter the number of quarters you have: "); strQuartes = dataIn.readLine(); intQuartes = Integer.parseInt(strQuartes) * 25; System.out.print("Enter the number of dimes you have: "); strDimes = dataIn.readLine(); intDimes = Integer.parseInt(strDimes) * 10; System.out.print("Enter the number of nickles you have: ...

### 85. rounding off a float to two decimal places    forums.oracle.com

I want to make a function where I shall pass a float and and integer. The float shall have to be rounded off to a value in the integer. Can anyone please suggest how to round off a float. E.g.: if the float is 12.56890 and I want to round it off to 2 decimal places, then it should be 12.57. ...