Course.java

public class Course {
    private String id;
    private String name;

    private Course(String ID, String NAME) {
        id = ID;
        name = NAME;
    }

    public static void main(String[] args) {
        Course course1 = new Course("COS01", "ProgrammingF");
        Course course2 = new Course("COS02", "ITIS");

        // output course1 course2 name
        System.out.println(course1.name);
        System.out.println(course2.name);

        System.out.println("########");
        course2 = course1;
        // re-set course2's name
        course2.setName("PF");

        // output course1 name
        System.out.println(course1.name);

        // course1 course 2 "identity hash code"
        System.out.println(course1);
        System.out.println(course2);
        // actually we can see that both course1 and course2 are having the same address
        // once the course2 = course1 is executed

    }

    private void setName(String newName) {
        name = newName;
    }
}