Java语言程序设计基础篇(原书第8版) 编程练习题10.9(课程类Course)

/*改写Course类（程序清单10-6）
* ·创建一个新的更大的数组并复制当前数组的内容来实现数组大小的自动增长
* ·实现dropStudent方法
* ·添加一个名为clear()的新方法，然后删除选某门课程的所有学生。
* 编写一个程序，创建一门课程，添加三个学生，删掉一个学生，然后显示这门课程的学生。*/
public class Exercise10_9 {
public static void main(String[] args) {
Course course1 = new Course("Data Structures");

course1.addStudent("Peter Jones");
course1.addStudent("Brian Smith");
course1.addStudent("Anne Kennedy");

course1.dropStudent("Anne Knenedy");

System.out.println("Number of students in course1: "
+ course1.getNumberOfStudents());
String[] students = course1.getStudents();
for(int i = 0; i < course1.getNumberOfStudents(); i++) {
if(i != course1.getNumberOfStudents() - 1) {
System.out.print(students[i] + ", ");
}
else
System.out.print(students[i]);
}

}
}

class Course{
private String courseName;
private String[] students = new String[100];
private int numberOfStudents;

public Course(String courseName) {
this.courseName = courseName;
}

public void addStudent(String student) {
students[numberOfStudents] = student;
numberOfStudents++;
}

public String[] getStudents() {
return students;
}

/*Return the number of students*/
public int getNumberOfStudents() {
return numberOfStudents;
}

public String getCourseName() {
return courseName;
}

/*Delete student*/
public void dropStudent(String student) {
for (int i = 0; i < numberOfStudents; i++) {
if (student == students[i]) {
for (int j = i; j < numberOfStudents - 1; j++) {
students[j] = students[j + 1];
}
students[students.length - 1] = null;
numberOfStudents--;
break;
}
}
}

/*Delete all the students in a course*/
public void clear() {
numberOfStudents = 0;
students = new String[0];
}
}