Java Tutorial/I18N/DecimalFormat

Arabic Digits

import java.awt.Font;
import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;
import java.text.NumberFormat;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class ArabicDigitsI18N extends JPanel {
  public ArabicDigitsI18N() {
    DecimalFormat df = (DecimalFormat) NumberFormat.getInstance();
    DecimalFormatSymbols dfs = df.getDecimalFormatSymbols();
    dfs.setZeroDigit("\u0660");
    df.setDecimalFormatSymbols(dfs);
    JLabel label = new JLabel(df.format(1234567.89));
    label.setFont(new Font("Lucida Sans", Font.PLAIN, 22));
    add(label);
  }
  public static void main(String[] argv) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.getContentPane().add("Center", new ArabicDigitsI18N());
    frame.pack();
    frame.setVisible(true);
  }
}

Displaying numbers with commas

import java.text.DecimalFormat;
public class Main {
  public static void main(String args[]) {
    double d = 123456.78;
    DecimalFormat df = new DecimalFormat("#####0.00");
    System.out.println(df.format(d));
  }
}

Display numbers in scientific notation

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String args[]) {
    NumberFormat formatter = new DecimalFormat();
    int maxinteger = Integer.MAX_VALUE;
    System.out.println(maxinteger); 
    formatter = new DecimalFormat("0.######E0");
    System.out.println(formatter.format(maxinteger));
    formatter = new DecimalFormat("0.#####E0");
    System.out.println(formatter.format(maxinteger));
    int mininteger = Integer.MIN_VALUE;
    System.out.println(mininteger); 
    formatter = new DecimalFormat("0.######E0");
    System.out.println(formatter.format(mininteger)); 
    formatter = new DecimalFormat("0.#####E0");
    System.out.println(formatter.format(mininteger));
    double d = 0.12345;
    formatter = new DecimalFormat("0.#####E0");
    System.out.println(formatter.format(d));
    formatter = new DecimalFormat("000000E0");
    System.out.println(formatter.format(d)); 
  }
}

Format a number with leading zeros

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] args) {
    NumberFormat formatter = new DecimalFormat("0000000");
    String number = formatter.format(2500);
    System.out.println("Number with lading zeros: " + number);
  }
}

new DecimalFormat("##00")

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("##00");
    String s = formatter.format(0); // 00
    System.out.println(s);
  }
}

new DecimalFormat("0.00")

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("0.00");
    String s = formatter.format(-.567); // -0.57
    System.out.println(s);
  }
}

new DecimalFormat("#.), append zero

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("#.000000");
    String s = formatter.format(-1234.567); 
    System.out.println(s);
  }
}
//-1234.567000

new DecimalFormat("#,###,###"), group

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("#,###,###");
    String s = formatter.format(-1234.567);
    System.out.println(s);
    s = formatter.format(-1234567.890);
    System.out.println(s);
  }
}
// -1,235
// -1,234,568

new DecimalFormat(".######"), keep fraction

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat(".######");
    String s = formatter.format(-1234.567); // -1234.567
    System.out.println(s);
  }
}//-1234.567

new DecimalFormat("#.######") more digits

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("#.######");
    String s = formatter.format(-1234.567); // -1234.567
    System.out.println(s);
  }
}

new DecimalFormat("#.#") two digits

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("#.#");
    String s = formatter.format(-1234.567); // -1234.6
    System.out.println(s);
  }
}

The 0 symbol shows a digit or 0 if no digit present

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("000000");
    String s = formatter.format(-1234.567);
    System.out.println(s);
    // number was rounded up
  }
}
//-001235

The . symbol indicates the decimal point

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat(".00");
    String s = formatter.format(-.567); // -.57
    System.out.println(s);
  }
}

The , symbol is used to group numbers

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat("#,###,###");
    String s = formatter.format(-1234.567);
    System.out.println(s);
    s = formatter.format(-1234567.890);
    System.out.println(s);
  }
}
// -1,235
// -1,234,568

The " symbol is used to quote literal symbols

import java.text.DecimalFormat;
import java.text.NumberFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    NumberFormat formatter = new DecimalFormat(""#"#");
    String s = formatter.format(-1234.567); 
    System.out.println(s);
  }
}
//-#1235

The ; symbol is used to specify an alternate pattern for negative values

public class Main{
public static void main(String[] argv) throws Exception{
    NumberFormat formatter = new DecimalFormat("#;(#)");
    String s = formatter.format(-1234.567);         // (1235)
    sysout
}}

Use group separators and show trailing zeros

import java.text.DecimalFormat;
public class Main {
  public static void main(String[] argv) throws Exception {
    DecimalFormat df = new DecimalFormat("#,.00;(#,.00)");
    System.out.println(df.format(7123.00));
  }
}