How to format 6 or 9 digit number like #,##,###

Question

How to format 6 or 9 digit number like #,##,### [for 6] and ##,##,##,### [for 9]

import java.text.DecimalFormat;
import java.text.NumberFormat;

public class CheckFormater {

public static void main(String[] args) {
    NumberFormat nf6 = new DecimalFormat("#,##,###");
    System.out.println(nf6.format(123456d));

    NumberFormat nf9 = new DecimalFormat("##,##,##,###");
    System.out.println(nf9.format(123456789d));
}

}

I am getting output as follows

123,456
123,456,789

I am expecting as follows

1,23,456
12,34,56,789

How to do costume formatting ?

From https://docs.oracle.com/javase/7/docs/api/java/text/DecimalFormat.html The grouping separator is commonly used for thousands, but in some countries it separates ten-thousands. The grouping size is a constant number of digits between the grouping characters. **If you supply a pattern with multiple grouping characters, the interval between the last one and the end of the integer is the one that is used.** You will have to make a String formatter. — Compass, Dec 15 '16 at 16:52

score 1 · Answer 1 · answered Dec 15 '16 at 17:08

You can use ICU4J

import com.ibm.icu.text.DecimalFormat;
import com.ibm.icu.text.DecimalFormatSymbols;

public class NewClass {
    public static void main(String[] args)  { 
        DecimalFormatSymbols dfs = new DecimalFormatSymbols();
        dfs.setGroupingSeparator(',');
        DecimalFormat nf6  = new DecimalFormat("#,##,###", dfs);
        DecimalFormat nf9  = new DecimalFormat("##,##,##,###", dfs);
        System.out.println(nf6.format(123456d));
        System.out.println(nf9.format(123456789d));
    }   
}

//prints
//1,23,456
//12,34,56,789

VHS · Answer 2 · 2016-12-15T18:15:46.753

Here is what Java Docs say:

The grouping separator is commonly used for thousands, but in some countries it separates ten-thousands. The grouping size is a constant number of digits between the grouping characters, such as 3 for 100,000,000 or 4 for 1,0000,0000. If you supply a pattern with multiple grouping characters, the interval between the last one and the end of the integer is the one that is used. So "#,##,###,####" == "######,####" == "##,####,####".

So in other words, you can only specify one grouping separator format at a time. Either a thousands separator or ten thousand separator or hundred separator. Even if you try to specify multiple formats in one, the method will use only the interval between the last one and the end of the integer. So in your case you are specifying "#,##,###" but the method will consider only the last comma and the number of digits afterwards which is 3 in your case. That's why the output is a thousand separator.

I was also hoping that selecting a proper locale should address this number formatting issue without needing to specify any pattern. E.g. in India, the numbers are in fact formatted the way you want. The first separator is thousand digit based and the rests are hundred digit based. So if I select Indian English locale, it should automatically address this requirement. But it doesn't.

NumberFormat nf6 = NumberFormat.getInstance(new Locale("en-IN"));       
System.out.println(nf6.format(54123756.523d));//Still prints 54,123,756.523 and not 5,41,23,756.523

So unfortunately there is no ready made way to achieve your objective unless you go for the recommendation of using third party libraries in the other answer. However you can always use a heck. It is not neat but achieves the objective. Maybe you can encapsulate this hack in a utility method or something:

    double number = 54123756.523d;
    int prefix = (int)number / 1000;

    NumberFormat nf1 = new DecimalFormat("#,##");
    String newPrefix = nf1.format(prefix);

    double remainder = number - (prefix * 1000);
    NumberFormat nf2 = new DecimalFormat("#,###.##");
    String newRemainder = nf2.format(remainder);

    String finalNum = newPrefix + "," + newRemainder;
    System.out.println("Formatted number is " + finalNum);

So see if you can live with the code sample suggested above. It is not ideal or efficient but will at least serve your purpose and won't need any third party libraries.

How to format 6 or 9 digit number like #,##,###

2 Answers2