Question

Design a JAVA class called Course. The class should contain: ○ The data fields courseName (String), numberOfStudents (int) and courseLecturer (String). ○ A constructor that constructs a Course object with the specified courseName, numberOfStudents and courseLecturer. ○ The relevant get and set methods for the data fields. ○ A toString() method that formats that returns a string that represents a course object in the following format: (courseName, courseLecturer, numberOfStudents) ● Create a new ArrayList called courses1, add 5 courses to it and print it out. ● Sort the List according the numberOfStudents and print it out. ● Swap the element at position 1 of the List with the element at position 2 and print it out. ● Create a new ArrayList called courses2. ● Using the addAll method add 5 courses to the courses2 List and print it out. ● Copy all of the courses from courses1 into courses2. ● Add the following two elements to courses2: ○ (Java 101, Dr. P Green, 55) ○ (Advanced Programming, Prof. M Milton, 93) ● Sort the courses in courses2 alphabetically according to the course name and print it out. ● Search for the course “Java 101” in courses2 and print out the index of the course in the List. ● Use the disjoint function to determine whether courses1 and courses2 have any elements in common and print out the result. ● In courses2, find the course with the most students and the course with the least students and print each out. Hi and thanx

Answer 1

Course.java:

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
class Course{
   String courseName;
   int numOfStudents;
   String courseLecturer;
   Course(String courseName, int numOfStudents, String courseLecturer) {
       this.courseName = courseName;
       this.numOfStudents = numOfStudents;
       this.courseLecturer = courseLecturer;
   }
   public void setCouseName(String courseName) {
       courseName = courseName;
   }
   public String getCourseName() {
       return courseName;
   }
   public void setNumOfStudents(int numOfStudents) {
       numOfStudents = numOfStudents;
   }
   public int getNumOfStudents() {
       return numOfStudents;
   }
   public void setCouseLecturer(String courseLecturer) {
       courseLecturer = courseLecturer;
   }
   public String getcourseLecturer() {
       return courseLecturer;
   }
   public String toString() {
       return "CourseName : "+courseName+" Number of Students : "+numOfStudents+" Course Lecturer: "+courseLecturer;
}
public static Comparator<Course> courseNameComparator = new Comparator<Course>() {

   public int compare(Course c1, Course c2) {
   String cs1 = c1.getCourseName().toUpperCase();
   String cs2 = c2.getCourseName().toUpperCase();

   //ascending order
   return cs1.compareTo(cs2);
}};
public static Comparator<Course> studentsComparator = new Comparator<Course>() {

   public int compare(Course c1, Course c2) {

   int s1 = c1.getNumOfStudents();
   int s2 = c2.getNumOfStudents();

   /*For ascending order*/
   return s1-s2;

}};

public static void main(String[] args) {
       ArrayList<Course> course1 = new ArrayList<Course>();
       course1.add(new Course("C", 10, "Leela"));
       course1.add(new Course("C++", 20, "Usha"));
       course1.add(new Course("Python", 5, "Teja"));
       course1.add(new Course("R", 2, "Ravi"));
       course1.add(new Course("C#", 15, "Kiran"));
       for(Course c: course1) {
           System.out.println(c);
       }
       System.out.println();
       Collections.sort(course1, Course.studentsComparator);
       for(Course c: course1) {
           System.out.println(c);
       }
       System.out.println();
       Collections.swap(course1, 1, 2);
       for(Course c: course1) {
           System.out.println(c);
       }
       System.out.println();
       ArrayList<Course> course2 = new ArrayList<Course>();
       course2.addAll(course1);
       for(Course c: course2) {
           System.out.println(c);
       }
       System.out.println();
       course2.add(new Course("Java 101",55, "Dr. P Green"));
       course2.add(new Course("Advanced Programming", 93, "Prof. M Milton"));
       for(Course c: course2) {
           System.out.println(c);
       }
       System.out.println();
       Collections.sort(course2, Course.courseNameComparator);
       for(Course c: course2) {
           System.out.println(c);
       }
       System.out.println();
       boolean isCommon = Collections.disjoint(course1, course2);
       System.out.println("No Common elements : "+isCommon);
       System.out.println();
       Collections.sort(course2, Course.studentsComparator);
       System.out.println("Course with minimum no of students : ");
       System.out.println(course2.get(0));
       System.out.println("Course with maximum no of students : ");
       System.out.println(course2.get(course2.size()-1));
   }
}

Output: