如何格式化字符串数字以包含逗号和圆角？

Question

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?

Answer 1

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));

Answer 2

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

Answer 3

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)

Answer 4

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

Answer 5

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 Eg 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.

Answer 6

you can also use the below solution

public static String getRoundOffValue(double value){
    DecimalFormat df = new DecimalFormat("##,##,##,##,##,##,##0.00");
    return df.format(value);
}

Answer 7

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);
}

Answer 8

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.

Answer 9

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.

Answer 10

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

Answer 11

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.