I'm turning this double into a string so I can display it on a TextView. I want the string to have 2 decimal places using String.format, but I don't know where to put it in this line of text.
Example.setText(Double.toString(dValue));
Any Ideas?
The quick and dirty way is to use a formatted String and specify the number of decimal points. Lately there's been a trend of suggesting the usage of a DecimalFormat instead since it will respect different locales and the usage of commas or points as a decimal separator.
//The suggested way lately
DecimalFormat formatter = new DecimalFormat("#0.00");
twoDecimals.setText(formatter.format(2.123145));
//The usual way with some caveats
twoDecimals.setText(String.format("%.2f",2.123));
I'm pretty sure it could also be done with formatted strings, but hey.. who am I to go against the trend.
Example.setText(String.format("%.2f", dValue));
.2 means 2 decimal places
f means it's a decimal type
Try this -
DecimalFormat df = new DecimalFormat("#.00");
Example.setText(df.format(dValue));
Related
So I use ...
System.out.printf("%.2f",variable);
and it works. But if the second decimal place is a 0, it just ignores the zero and gives the answer to one decimal place. How can I get two decimal places including the zero?
Thanks.
you can use DecimalFormat like this
DecimalFormat decimalFormat = new DecimalFormat("#0.00");
String format = decimalFormat.format(variable);
I've been looking for a way to convert a double, which is big to a readable String.
The double:
double myValue = 1000000000000000.123456789;
Which when printed out gives me this:
1.0000000000000001E15
The result im looking for would be this:
1.000.000.000.000.000,12
I've been searching for this for days but i couldn't find a solution for this unfortunately so i thought maybe i could ask here:) thanks for reading!
If you are interested in setting your own separator characters (i.e. not using the default for your locale) then you can do the following:
DecimalFormatSymbols symbols = new DecimalFormatSymbols();
symbols.setGroupingSeparator('.');
symbols.setDecimalSeparator(',');
DecimalFormat format = new DecimalFormat("#,##0.00", symbols);
System.out.println(format.format(100000000000.123456789));
You also mentioned rounding in your question. Unfortunately that has nothing to do with the formatting at all - you are hitting the limit of precision for double in Java. A double is a 64 bit floating points which gives you 15-16 digits of precision. You can verify this by checking the following expression in Java: 1000000000000000.123456789 == 1000000000000000.1.
So, in reality what is happening is that once you have assigned your value to the myValue variable it has already been rounded. It doesn't matter how you format it from that point you won't get the precision back.
If you need greater precision than double you should look at BigDecimal that supports arbitrary precision.
I am using DecimalFormatter to read in formatted decimal string values and convert them to float. However, when I run:
DecimalFormat formatter = new DecimalFormat("####,####.00");
String floatStr = "177,687.71";
float val1 = formatter.parse(floatStr).floatValue();
System.out.println(val1);
...I get 177678.7 instead of 177678.71. Why is this? How do I avoid rounding the hundredths place?
Thanks!
You appear to need more precision than a float to represent that number.
Taking the formatter out of the picture:
Float.parseFloat("177687.71");
177687.7 // Ouch
Double.parseDouble("177687.71");
177687.71 // Ok
It seems that you'll need to use a double instead.
If this is for representing money though as #Dawood is suggesting , then yes, do not use floating types to represent money, since they are estimations and will accumulate errors over time. A format like BigDecimal would be more appropriate, or even just storing an integer representing cents. Money is not something that you want to subject to rounding errors.
I have different float values like
0.0000009
8145.32
123.00001
1235.01000
I want them showing to a TextView or converting them to string without getting an exponential notation.
when I use String.format("%.8f", num), It is getting random values after the real number ( num = 8145.32 -> 8145.32539487).
Help me, Thank you
Try this use DecimalFormat
DecimalFormat is a concrete subclass of NumberFormat that formats decimal numbers. It has a variety of features designed to make it possible to parse and format numbers in any locale, including support for Western, Arabic, and Indic digits
SAMPLE CODE
Double value = 123456434.678;
DecimalFormat decimalFormat = new DecimalFormat("#0.00");
Log.e("MY_VALUES", decimalFormat.format(value));
OUTPUT
com.example.nilesh.testapp E/MY_VALUES: 123456434.68
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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.