How to format a number in java?

**kamina23** · 20-01-2010

Hi friends,
I am new to this forum. I am last year B.Sc.I.T. I am working on project where I use java as front end. I want to display number in particular format. Can anyone tell me How to format a number in java? Please help me to find answer. Thank you.

**Praetor** · 20-01-2010

You can format a number in java in following ways. If you want to display some numbers that is formatted to a certain pattern in your project then you can utilize NumberFormat and DecimalFormat class to give you the format that you want. Here I had written example that will show you how to do it.

Code:

package org.kodejava.example.text;
 
import java.text.DecimalFormat;
import java.text.NumberFormat;
 
public class DecimalFormat
{
    public static void main(String[] args)
    {
        NumberFormat F1 = new DecimalFormat("#0.00");
        System.out.println(M);
       
        System.out.println(F1.format(M));
    }
}

**Katty** · 20-01-2010

You have to use pattern of special characters to specify the format of the number. Following example demonstrates some of the characters.

Code:

// The 0 symbol shows a digit or 0 if no digit present 
NumberFormat F1 = new DecimalFormat("000000"); 
String S = F1.format(-4321.567); // -004321

Code:

// The # symbol shows a digit or nothing if no digit present 
F1 = new DecimalFormat("##"); 
S = F1.format(-4321.567); // -4321 
S = F1.format(0); // 0 
F1 = new DecimalFormat("##00");
S = F1.format(0); // 00

**kelfro** · 20-01-2010

You can format number in following ways.

Code:

import java.text.NumberFormat;
import java.util.Locale;

public class NFD {

  static public void displayNumber(Locale currentLocale) {

    Integer q = new Integer(65231);
    Double a = new Double(58741.246);
    NumberFormat nFormatter;
    String qOut;
    String aOut;

    nFormatter = NumberFormat.getNumberInstance(cLocale);
    qOut = numberFormatter.format(q);
    aOut = numberFormatter.format(amount);
    System.out.println(qOut + "   " + cLocale.toString());
    System.out.println(aOut + "   " + cLocale.toString());
  }

  static public void displayCurrency(Locale currentLocale) {

    Double c = new Double(3652159.21);
    NumberFormat cFormatter;
    String cOut;

    cFormatter = NumberFormat.getCurrencyInstance(cLocale);
    cOut = currencyFormatter.format(c);
    System.out.println(currencyOut + "   " + cLocale.toString());
  }

  static public void displayPercent(Locale cLocale) {

    Double p = new Double(0.75);
    NumberFormat pFormatter;
    String pOut;

    pFormatter = NumberFormat.getPInstance(currentLocale);
    pOut = pFormatter.format(p);
    System.out.println(pOut + "   " + cLocale.toString());
  }

  static public void main(String[] args) {

    Locale[] locales = { new Locale("fr", "FR"), new Locale("de", "DE"),
        new Locale("en", "US") };

    for (int h = 0; h < locales.length; h++) {
      System.out.println();
      displayNumber(locales[h]);
      displayCurrency(locales[h]);
      displayPercent(locales[h]);
    }
  }

}

**kelfro** · 20-01-2010

Hey there are different way to format number. I had written 3 example to do this. Just go through it.

Code:

double p = 2.6854;
System.out.println(p); // p is 2.6854

int q = 3;
BigDecimal d = new BigDecimal(p);

// setScale is immutable
d = d.setScale(decimalPlaces, BigDecimal.ROUND_HALF_UP);
p = d.doubleValue();

System.out.println(p); // p is 2.68

Code:

d = (float) (Math.round(n*1200.0f)/200.0f);

Code:

DecimalFormat cms = new DecimalFormat( "#,###,###,##0.00" );
double fg = 100.2397;
double fg2erd = new Double(dfg.format(dfg)).doubleValue();

// The value of fg2erddec will be 200.23