The java.text.DecimalFormat class is used for formatting numbers as per customized format and as per locale.

Example – Format Numbers

In this example, we”re formatting numbers based on a given pattern.

import java.text.DecimalFormat;

public class I18NTester {
   public static void main(String[] args) {
      String pattern = "####,####.##";
      double number = 123456789.123;
      
      DecimalFormat numberFormat = new DecimalFormat(pattern);

      System.out.println(number);
      
      System.out.println(numberFormat.format(number));
   }
}

Output

It will print the following result.

1.23456789123E8
1,2345,6789.12