This question already has answers here:
How to round a number to n decimal places in Java
(39 answers)
Closed 9 years ago.
In this program I'm printing a value from a calculation of type double to the screen.But at present the calculation is giving 14 decimal places.My question is,is there a facility in Java to wrap the output statement in that could specify the amount of decimal places?For example round(mark1,2)
The way it is printed at present is like this:
double markOne = intent.getDoubleExtra("number1", 0);
result1.setText(String.valueOf(markOne)+"mm");
Is it possible to wrap the setText in a Java method or would I have to create a custom format?Could someone give me an example of this with my code? Thanks
You could use a decimal formatter
DecimalFormat df = new DecimalFormat("#.##");
System.out.print(df.format(d));
I think it's better to use BigDecimal type instead of Double.
You could do
BigDecimal myValue= new BigDecimal(12.3577);
myValue= myValue.setScale(2, BigDecimal.ROUND_HALF_UP);
And myValue will be 12.36
I hope this will help
Try this:
int decimalPlaces = 2;
markOne = double(int(markOne*Math.pow(10, decimalPlaces)))/Math.pow(10, decimalPlaces);
Related
This question already has answers here:
The accuracy of a double in general programming and Java
(2 answers)
Closed 2 years ago.
I am trying rounding and format techniques in Java as I have to keep my values in database with some specific formats.
My database column has the data precision of 18,4 which means 14 integers and 4 decimal places at max.
Now I am trying max possible value case which is 99999999999999.9999. When I execute the below code, I am getting a rounded value of 1000000000000000. However, I want to store the exact value provided.
Can anyone suggest to keep it as it is in java variable?
DecimalFormat df2 = new DecimalFormat( "#.####" );
df2.setRoundingMode(RoundingMode.CEILING);
double number = Double.parseDouble("99999999999999.9999");
System.out.println("Format: " + df2.format(number));
You can use BigDecimal
BigDecimal number = new BigDecimal("99999999999999.9999");
This question already has answers here:
How do I print a double value without scientific notation using Java?
(18 answers)
Closed 6 years ago.
I want to format a double so, that there's no scientific notation (the E letter) showing when I have a number larger than a million or so.
I have already formatted the double to have only two decimals.
as in
DecimalFormat dFormat = new DecimalFormat("0.00");
but even with that, I'm seeing 10007999.00 as 1.001511661E7 on the screen.
I don't want to see it in that form (can't really think of why anyone would...)
How to format the double so, that it is showing as a normal number, not some letters in it. Thank you.
A 5-minute search on Google brought me here:
How to print double value without scientific notation using Java?
This is what you want right?
Here's the same thing, but in a function:
public static String dNoScience(double d) {
return String.format("%.0f\n", d);
}
This question already has answers here:
Format double value in scientific notation
(4 answers)
How to round a number to n decimal places in Java
(39 answers)
Closed 6 years ago.
I have been working with big numbers (with more that 20 digits) and for that reason I use Double . The form I get the numbers is like this 8.653762536765E28.
What I want to do is just display the first 2 decimal digits. I want it like 8.65E28.
I tried to find about formatting double values but I wan't able to do it. The result I was getting was 86537...12312.00 .
What do you thing is a good approach for this case? How can I manage only the digits in front of the E (the base) and not the whole number?
I think this is what you want to achieve:
double d = 8.653762536765E28;
DecimalFormat df = new DecimalFormat("0.00E0");
System.out.print(df.format(d));
This question already has answers here:
How to round a number to n decimal places in Java
(39 answers)
Closed 6 years ago.
I was looking for a simple way to round a double value to 10 digits but I didn't found even one way that look good to me, everything was too complicated.
I hope someone could help me, for example: the value 0.83426945721236485 will become 0.8342694572
Thank you in advance.
Simple.
DecimalFormat df = new DecimalFormat("0.0000000000");
System.out.println(df.format(0.83426945721236485));
Take a look at the documentation:
https://docs.oracle.com/javase/8/docs/api/java/text/DecimalFormat.html
Decimal places are not meaningful internally for double, because it is a binary floating point.
You can, of course, choose to display it in any format supported by DecimalFormat, as suggested in a prior answer.
If you want a ten decimal place internal representation, you should be using BigDecimal with scale factor 10.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
How to round a number to n decimal places in Java
I am having difficulties rounding a float to two decimal places. I have tried a few methods I have seen on here including simply just using Math.round(), but no matter what I do I keep getting unusual numbers.
I have a list of floats that I am processing, the first in the list is displayed as 1.2975118E7. What is the E7?
When I use Math.round(f) (f is the float), I get the exact same number.
I know I am doing something wrong, I just am not sure what.
I just want the numbers to be in the format x.xx. The first number should be 1.30, etc.
1.2975118E7 is scientific notation.
1.2975118E7 = 1.2975118 * 10^7 = 12975118
Also, Math.round(f) returns an integer. You can't use it to get your desired format x.xx.
You could use String.format.
String s = String.format("%.2f", 1.2975118);
// 1.30
If you're looking for currency formatting (which you didn't specify, but it seems that is what you're looking for) try the NumberFormat class. It's very simple:
double d = 2.3d;
NumberFormat formatter = NumberFormat.getCurrencyInstance();
String output = formatter.format(d);
Which will output (depending on locale):
$2.30
Also, if currency isn't required (just the exact two decimal places) you can use this instead:
NumberFormat formatter = NumberFormat.getNumberInstance();
formatter.setMinimumFractionDigits(2);
formatter.setMaximumFractionDigits(2);
String output = formatter.format(d);
Which will output 2.30
You can make use of DecimalFormat to give you the style you wish.
DecimalFormat df = new DecimalFormat("0.00E0");
double number = 1.2975118E7;
System.out.println(df.format(number)); // prints 1.30E7
Since it's in scientific notation, you won't be able to get the number any smaller than 107 without losing that many orders of magnitude of accuracy.
Try looking at the BigDecimal Class. It is the go to class for currency and support accurate rounding.