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how to display a string with two decimal places which is carrying currency value in dollar

I'm taking a value from the mobile application which I'm getting in string format something like "$000"(which actually $0.00 ) similarly I want to convert all the value into two decimal place say if I get "$279"(which is in application actually $2.79)
I don't know the correct approach because further in I have compair this value to some other string.
so I want to keep this as String but at the same time I want to put decimal after two place always whatever the number.
I tried to Decimal formatter for money but gave me "object as a number format" exception
sends
String accLastFourDigits, getCurrAmt, currAmt;
getCurrAmt = getDriver().findElement(by("overview.current_balance")).getText();
DecimalFormat money = new DecimalFormat("$0.00");
currAmt = money.format(getCurrAmt);

You could use builtin NumberFormat provided by JAVA to parse different country Currencies as shown below. Also I am dividing the resulting number by 100, so as to satisfy the requirement, that $978 is read as 9.78.
NumberFormat usFormat = NumberFormat.getCurrencyInstance(Locale.US);
String currencyValue = "$100";
try {
System.out.println(usFormat.parse(currencyValue).intValue()/100);
}catch(ParseException e) {
e.printStackTrace();
}
Here, I am setting the currency to US and then parsing a string with dollar sign.
You could also use the format method of NumberFormat to print the currency value in respective currency formats, as shown below
NumberFormat usFormat = NumberFormat.getCurrencyInstance(Locale.US);
String currencyValue = "$100";
try {
Number value = usFormat.parse(currencyValue).intValue()/100;
System.out.println("Number value : " + value);
System.out.printf("In Currency : "+usFormat.format(value));
}catch(ParseException e) {
e.printStackTrace();
}

You have this exception because format method expect number type argument. What you need to do then is to remove all non digits characters from the input string
getCurrAmt = getCurrAmt.replaceAll("[^\\d.]", ""); // please note that replaceAll method has poor performance
and parse it to Integer when calling format method
money.format(Integer.parseInt(getCurrAmt))
As pointed out replaceAll method is not very efficient because it needs to compile Pattern every single time and it's better to use Matcher - you can read about this in this topic:
String replaceAll() vs. Matcher replaceAll() (Performance differences)

How about this?
String inputStr = "$279";
NumberFormat usCurrency = NumberFormat.getCurrencyInstance(Locale.US);
usCurrency.setParseIntegerOnly(true);
long num = (Long)usCurrency.parse(inputStr);
BigDecimal amount = new BigDecimal(num);
amount = amount.scaleByPowerOfTen(-2);
log.info("amount: {}", usCurrency.format(amount));

Java - Is it possible to figure out the DecimalFormat of a string

I am trying to figure out how to, given a decimal through a String calculate the number of significant digits so that I can do a calculation to the decimal and print the result with the same number of significant digits. Here's an SSCCE:
import java.text.DecimalFormat;
import java.text.ParseException;
public class Test {
public static void main(String[] args) {
try {
DecimalFormat df = new DecimalFormat();
String decimal1 = "54.60"; // Decimal is input as a string with a specific number of significant digits.
double d = df.parse(decimal1).doubleValue();
d = d * -1; // Multiply the decimal by -1 (this is why we parsed it, so we could do a calculatin).
System.out.println(df.format(d)); // I need to print this with the same # of significant digits.
} catch (ParseException e) {
e.printStackTrace();
}
}
}
I know DecimalFormat is to 1) tell the program how you intend your decimal to be displayed (format()) and 2) to tell the program what format to expect a String-represented decimal to be in (parse()). But, is there a way to DEDUCE the DecimalFormat from a parsed string and then use that same DecimalFormat to output a number?

Use BigDecimal:
String decimal1 = "54.60";
BigDecimal bigDecimal = new BigDecimal(decimal1);
BigDecimal negative = bigDecimal.negate(); // negate keeps scale
System.out.println(negative);
Or the short version:
System.out.println((new BigDecimal(decimal1)).negate());

Find it via String.indexOf('.').
public int findDecimalPlaces (String input) {
int dot = input.indexOf('.');
if (dot < 0)
return 0;
return input.length() - dot - 1;
}
You can also configure a DecimalFormat/ NumberFormat via setMinimumFractionDigits() and setMaximumFractionDigits() to set an output format, rather than having to build the pattern as a string.

int sigFigs = decimal1.split("\\.")[1].length();
Computing the length of the string to the right of the decimal is probably the easiest method of achieving your goal.

If you want decimal places, you can't use floating-point in the first place, as FP doesn't have them: FP has binary places. Use BigDecimal, and construct it directly from the String. I don't see why you need a DecimalFormat object at all.

You could convert a number string to a format string using regex:
String format = num.replaceAll("^\\d*", "#").replaceAll("\\d", "0");
eg "123.45" --> "#.00" and "123" --> "#"
Then use the result as the pattern for a DecimalFormat
Not only does it work, it's only one line.

Java negative bigdecimal value with braces

I have a string that I'm trying to parse into a BigDecimal. I'm using the following regex to strip all non currency symbols with the exception of -,.()$. Once it has been stripped, I'm then trying to create a BigDecimal with the remaining value. The problem begins when a negative value comes across in brackets. Does anybody have any suggestions on how to repair this instance?
(1000.00) fails
I'm assuming I must somehow convert the brackets to a negative sign.
code sample.
public BigDecimal parseClient(Field field, String clientValue, String message) throws ValidationException {
if (clientValue == null) {
return null;
}
try {
clientValue = clientValue.replaceAll( "[^\\d\\-\\.\\(\\)]", "" );
return new BigDecimal(clientValue.toString());
} catch (NumberFormatException ex) {
throw new ValidationException(message);
}
}

You will need to detect the ( and ) characters yourself, then strip them out, create a BigDecimal from the rest of the string, and negate it.
if (clientValue.startsWith('(') && clientValue.endsWith(')'))
{
return new BigDecimal(clientValue.substring(1, clientValue.length() - 1)).negate();
}
else
{
return new BigDecimal(clientValue);
}

What makes you think parentheses are correctly interpreted by BigDecimal? (1000.00) is incorrect input according to the documentation. You must use - symbol (-1000.00). Supported format is strictly defined in JavaDoc. In general it's optional symbol (+ or -) followed by digits, dot (.) and exponent.
For example this is valid input: -1.1e-10.

DecimalFormat is a more appropriate tool for the job:
DecimalFormat myFormatter = new DecimalFormat("¤#,##0.00;(¤#,##0.00)");
myFormatter.setParseBigDecimal(true);
BigDecimal result = (BigDecimal) myFormatter.parse("(1000.00)");
System.out.println(result); // -1000.00 for Locale.US
System.out.println(myFormatter.parse("($123,456,789.12)")); // -123456789.12
As you can see, not only will it deal with negative patterns, but also with currency signs, decimal and grouping separators, localization issues, etc.
Take a look at The Java Tutorials: Customizing Formats for further info.

Howto format number with DecimalFormat with optional scientific notation

I am using a pattern "#0.00##" to format numbers, it works as expected for most input. But sometimes sources number are smaller ie: 6.84378E-05, and gets converted into "0,0001".
Is it possible to format only such numbers (not fitting standard pattern) using scientific notation? leaving all "normal" numbers intact? with single pattern.
I have to use only a single DecimalFormat pattern, without any extra code.
EDIT: To better explain why I need single DecimalFormat : I am using an external library and can only define a pattern to configure output.

You can have distinct patterns only for positive and negative values.You should do something like:
public class DecimalScientificFormat extends DecimalFormat {
private static DecimalFormat df = new DecimalFormat("#0.00##");
private static DecimalFormat sf = new DecimalFormat("0.###E0");
#Override
public StringBuffer format(double number, StringBuffer result, FieldPosition fieldPosition) {
String decimalFormat = df.format(number);
return (0.0001 != number && df.format(0.0001).equals(decimalFormat)) ? sf.format(number, result, fieldPosition) : result.append(decimalFormat);
}
}

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.