09/02/07 22:33:53
>144
// P67_144.java
public class P67_144 {
public static void main(String[] args) {
Student first1 = new First("20123456");
Student first2 = new First("20123457");
Student second1 = new Second("19123458");
Student second2 = new Second("19123459");
Student third1 = new Third("18123450");
Student third2 = new Third("18123451");
Student fourth1 = new Fourth("17123452");
Student fourth2 = new Fourth("17123453");
Student[] students = new Student[] { first1, first2, second1, second2, third1, third2, fourth1, fourth2, };
for(Student student : students)
System.out.println(student.getGrade() + ":" + student.getNumber());
}
}
// Student.java
public abstract class Student {
private String number;
public Student(String number) { this.number = number; }
public abstract String getGrade();
public String getNumber() { return number; }
}