formatreals.java

《A first book of java》by Gary J.Bronson 北大出版社

import java.text.*;     // needed to access the NumberFormat methods
public class FormatReals
{
  public static void main(String[] args)
  {
    NumberFormat num = NumberFormat.getInstance();
    num.setMinimumIntegerDigits(2);
    num.setMinimumFractionDigits(2);
    num.setMaximumFractionDigits(6);
    
    System.out.println(num.format(3));
    System.out.println(num.format(43));
    System.out.println(num.format(143));
    System.out.println(num.format(2143));
    System.out.println(num.format(3.7));
    System.out.println(num.format(33.77));
    System.out.println(num.format(333.777));
    System.out.println(num.format(3333.4444444));
    System.out.println(num.format(3333.7777777));
  }
}