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Converting BigDecimal to double value

I want to ask how to transform all my String to double with exponential.
when I use the string that length is over seven it's doing fine .
new BigDecimal("12345678").doubleValue() => 1.2345678E7
but seven and under I can't export exponential number.
new BigDecimal("1234567").doubleValue() => 1234567.0
what I want is like 1.234567E6.
Is there any way to do this? I've been searching for a while ,but got nothing.
The problem is the type I return must be double . After transforming the value under seven I can only get the value without exponential.
double test = new BigDecimal("1.234567E6").doubleValue() ;//output 1234567.0
but I need it to be 1.234567E6 and return to caller. Is that Impossible?

You should know that 1.2345678e7 and 12345678.0 are exactly the same value, only with different textual representations. You could represent 1234567.0 as 1.234567e6 too. Also exactly the same double, just a different way of writing it out.
The default output shows values with more than a certain number of significant digits in exponential format ("e-form"), otherwise as plain decimal format.
So you may want to change the formatting of the doubles you receive. This can be done with e.g. DecimalFormat or String.format() or similar. That does not change the doubles, only the way they are presented in a string.

For your problem, you want to convert the value to the BigDecimal with exponential, you can use the DecimalFormat. You can also change the scale for the output value digits.
import java.math.*;
import java.text.*;
public class HelloWorld{
public static void main(String []args){
double a = new BigDecimal("1234567").doubleValue();
String b;
System.out.println(a);
NumberFormat formatter = new DecimalFormat("0.0E0");
formatter.setRoundingMode(RoundingMode.DOWN);
formatter.setMinimumFractionDigits(5); //<---Scale
b = formatter.format(a);
System.out.println(b);
}
}
The output will be like:
1234567.0 //Unformatted Value
1.23456E6 //Formatted Value

See the section about Scientific Notation in java.text.DecimalFormat.
For example,
DecimalFormat scientificFormat = new DecimalFormat("0.###E0");
System.out.println(scientificFormat.format(BigDecimal.valueOf(123456L)));
System.out.println(scientificFormat.format(BigDecimal.valueOf(1234567L)));
scientificFormat.setMinimumFractionDigits(10);
System.out.println(scientificFormat.format(BigDecimal.valueOf(12345678L)));
would give you
1,235E5
1,235E6
1,2345678000E7
Change the pattern to match what you're looking for.

Remove decimals after a numeric value in java

Hi I have a excel file reading application which reads every cell in the file.
whenever a cell contains a numeric value the app is treating it a numeric cell.
For example the cell contains (40002547) the application will treat this as numeric cell. I cab get the value by using this code:
SONum = String.valueOf(cellSONum.getNumericCellValue());
Well that works fine. My Problem is it appends decimal at the end of the string. it will be (40002547.0). I need it to be as is. Thanks in advance

It's because cellSONum.getNumericCellValue() is returning a floating point type. If you force it to an integer before calling valueOf(), you should get the string representation in an integral form, if indeed that's what you want for all possibilities:
SONum = String.valueOf((int)cellSONum.getNumericCellValue());
You can see this in the following code:
class Test {
public static void main(String[]args) {
double d = 1234;
System.out.println(String.valueOf(d));
System.out.println(String.valueOf((int)d));
}
}
which outputs:
1234.0
1234
However, if you want to just get rid of .0 at the end of any string but allow non-integral values to survive, you can just remove the trailing text yourself:
class Test {
public static void main(String[]args) {
double d1 = 1234;
double d2 = 1234.567;
System.out.println(String.valueOf(d1).replaceFirst("\\.0+$", ""));
System.out.println(String.valueOf(d2).replaceFirst("\\.0+$", ""));
}
}
That snippet outputs:
1234
1234.567

Try with split().
SONum = String.valueOf(cellSONum.getNumericCellValue());
SONum = SONum.split("\\.")[0];
When you split 40002547.0 with . ,the split function returns two parts and the first one you need.

If you want to be sure you are not cutting of any valid decimals, you can use regexp also:
String pattern = "\.0+"; // dot followed by any number of zeros
System.out.println(String.valueOf(cellSONum.getNumericCellValue()).replaceAll(pattern, ""));
More on java regexp for example: http://www.vogella.com/articles/JavaRegularExpressions/article.html

As PaxDiablo also mentions, cellSONum.getNumericCellValue() returns a floating point.
You can cast this to Long or int to get rid of all behind the '.'
String SONum = String.valueOf(cellSONum.getNumericCellValue().longValue());
used as example:
String SONum = String.valueOf((new Double(0.5)).longValue());

SONum = ""+cellSONum.getNumericCellValue().split(".")[0];

try
double value = 23.0;
DecimalFormat df = new DecimalFormat("0.##");
System.out.println("bd value::"+ df.format(value))

Consider using BigDecimal.
You could simply say
BigDecimal scaledDecimal = new BigDecimal(value).setScale(0, RoundingMode.HALF_EVEN);

This will help in case your input is String and you need result also in String
1). Convert the string to Double using Double.parseDouble,
2). Type cast to int, then convert to string using String.valueOf()
private String formatText(String text) {
try {
return String.valueOf((int) Double.parseDouble(text));
} catch (NumberFormatException e) {
return text;
}
}

You can do Explicit type casting to remove the decimals,
double desvalue = 3.586;
int value = (int)desvalue;

Avoid round number when casting a float to string

I need avoid round number when casting a float to string, I need the number is exactly the same.
In this moment if I make this:
String value = String.valueOf(1234567.99);
The the value = 1234568.0 ,so I need the value = 1234567.99 after casting.

1234567.99 can't be exactly represented as a float. The nearest float is actually equal to 1234568.
If you want more precision, you can use a double: 1234567.99d will do what you expect.
You can run this simple test to check it (it is in Java but easily transposable on android by replacing the println):
public static void main(String[] args) {
float f = 1234567.99f;
double d = 1234567.99d;
System.out.println(new BigDecimal(f));
System.out.println(new BigDecimal(d));
}
prints:
1234568
1234567.98999999999068677425384521484375
Note: String.valueOf(double) does round the double to another representation, with less decimals, of the same double. In other words, as you see above 1234567.99d can't be represented as a double and the nearest double is 1234567.98999999999068677425384521484375. But String.valueOf figures it out and uses the first representation of that double (with only 2 decimals) since they are effectively the same double according to the specifications of the language.

String.valueOf() never round off any number you have some other issue but you can try it as:
String value = ""+1234567.99;

String s = Double.toString(1234567.99);
update: for more control over the string's format, use DecimalFormat and DecimalFormatSymbols
For example:
java.text.DecimalFormat formater = new java.text.DecimalFormat();
formater.setMinimumFractionDigits(0);
formater.setMaximumFractionDigits(3);
formater.setGroupingUsed(false);
java.text.DecimalFormatSymbols dfs = new java.text.DecimalFormatSymbols();
dfs.setNaN("NaN");
formater.setDecimalFormatSymbols(dfs);
String s = formater.format(1234567.99);

How can I format a String number to have commas and round?

What is the best way to format the following number that is given to me as a String?
String number = "1000500000.574" //assume my value will always be a String
I want this to be a String with the value: 1,000,500,000.57
How can I format it as such?

You might want to look at the DecimalFormat class; it supports different locales (eg: in some countries that would get formatted as 1.000.500.000,57 instead).
You also need to convert that string into a number, this can be done with:
double amount = Double.parseDouble(number);
Code sample:
String number = "1000500000.574";
double amount = Double.parseDouble(number);
DecimalFormat formatter = new DecimalFormat("#,###.00");
System.out.println(formatter.format(amount));

This can also be accomplished using String.format(), which may be easier and/or more flexible if you are formatting multiple numbers in one string.
String number = "1000500000.574";
Double numParsed = Double.parseDouble(number);
System.out.println(String.format("The input number is: %,.2f", numParsed));
// Or
String numString = String.format("%,.2f", numParsed);
For the format string "%,.2f" - "," means separate digit groups with commas, and ".2" means round to two places after the decimal.
For reference on other formatting options, see https://docs.oracle.com/javase/tutorial/java/data/numberformat.html

Given this is the number one Google result for format number commas java, here's an answer that works for people who are working with whole numbers and don't care about decimals.
String.format("%,d", 2000000)
outputs:
2,000,000

Once you've converted your String to a number, you can use
// format the number for the default locale
NumberFormat.getInstance().format(num)
or
// format the number for a particular locale
NumberFormat.getInstance(locale).format(num)

I've created my own formatting utility. Which is extremely fast at processing the formatting along with giving you many features :)
It supports:
Comma Formatting E.g. 1234567 becomes 1,234,567.
Prefixing with "Thousand(K),Million(M),Billion(B),Trillion(T)".
Precision of 0 through 15.
Precision re-sizing (Means if you want 6 digit precision, but only have 3 available digits it forces it to 3).
Prefix lowering (Means if the prefix you choose is too large it lowers it to a more suitable prefix).
The code can be found here. You call it like this:
public static void main(String[])
{
int settings = ValueFormat.COMMAS | ValueFormat.PRECISION(2) | ValueFormat.MILLIONS;
String formatted = ValueFormat.format(1234567, settings);
}
I should also point out this doesn't handle decimal support, but is very useful for integer values. The above example would show "1.23M" as the output. I could probably add decimal support maybe, but didn't see too much use for it since then I might as well merge this into a BigInteger type of class that handles compressed char[] arrays for math computations.

you can also use the below solution
public static String getRoundOffValue(double value){
DecimalFormat df = new DecimalFormat("##,##,##,##,##,##,##0.00");
return df.format(value);
}

public void convert(int s)
{
System.out.println(NumberFormat.getNumberInstance(Locale.US).format(s));
}
public static void main(String args[])
{
LocalEx n=new LocalEx();
n.convert(10000);
}

You can do the entire conversion in one line, using the following code:
String number = "1000500000.574";
String convertedString = new DecimalFormat("#,###.##").format(Double.parseDouble(number));
The last two # signs in the DecimalFormat constructor can also be 0s. Either way works.

Here is the simplest way to get there:
String number = "10987655.876";
double result = Double.parseDouble(number);
System.out.println(String.format("%,.2f",result));
output:
10,987,655.88

The first answer works very well, but for ZERO / 0 it will format as .00
Hence the format #,##0.00 is working well for me.
Always test different numbers such as 0 / 100 / 2334.30 and negative numbers before deploying to production system.

According to chartGPT
Using DecimalFormat:
DecimalFormat df = new DecimalFormat("#,###.00");
String formattedNumber = df.format(yourNumber);
Using NumberFormat:
NumberFormat nf = NumberFormat.getNumberInstance();
nf.setGroupingUsed(true);
String formattedNumber = nf.format(yourNumber);
Using String.format():
String formattedNumber = String.format("%,.2f", yourNumber);
Note: In all the above examples, "yourNumber" is the double value that you want to format with a comma. The ".2f" in the format string indicates that the decimal places should be rounded to 2 decimal places. You can adjust this value as needed.

How to convert a string 3.0103E-7 to 0.00000030103 in Java?

How to convert a string 0E-11 to 0.00000000000 in Java? I want to display the number in non scientific notations. I've tried looking at the number formatter in Java, however I need to specific the exact number of decimals I want but I will not always know. I simply want the number of decimal places as specificed by my original number.

Apparently the correct answer is to user BigDecimal and retrieve the precision and scale numbers. Then use those numbers in the Formatter. Something similar like this:
BigDecimal bg = new BigDecimal(rs.getString(i));
Formatter fmt = new Formatter();
fmt.format("%." + bg.scale() + "f", bg);
buf.append( fmt);

Using BigDecimal:
public static String removeScientificNotation(String value)
{
return new BigDecimal(value).toPlainString();
}
public static void main(String[] arguments) throws Exception
{
System.out.println(removeScientificNotation("3.0103E-7"));
}
Prints:
0.00000030103

I would use BigDecimal.Pass your string into it as a parameter and then use String.format to represent your newly created BigDecimal without scientific notation.
Float or Double classes can be used too.

double d = Double.parseDouble("7.399999999999985E-5");
NumberFormat formatter = new DecimalFormat("###.#####");
String f = formatter.format(d);
System.out.println(f); // output --> 0.00007

I haven't tried it, but java.text.NumberFormat might do what you want.