complete7_4.java

北京大学出版社的

package questions.c7;
public class Complete7_4 {
   public static void f( Number n ) {
      // your code here
   }
   public static void main( String[] args ) {
      f( new Integer( 23 ) );
      f( new Long( 2356789 ) );
      f( new Double( 3.14 ) );
   }
}