Question

Create a class named CollegeCourse that includes the following data fields:

• dept (String) - holds the department (for example, ENG)
• id (int) - the course number (for example, 101)
• credits (double) - the credits (for example, 3)
• price (double) - the fee for the course (for example, $360).

All of the fields are required as arguments to the constructor, except for the fee, which is calculated at $120 per credit hour. Include a display() method that displays the course data. For example, if dept is 'SE', id is 225, and credits is 3, the output from display() should be:

SE225
Non-lab course
3.0 credits
Total fee is $360.0

Create a subclass named LabCourse that adds $50 to the course fee. Override the parent class display() method to indicate that the course is a lab course and to display all the data. For example, if dept is 'BIO', id is 201, and credits is 4, the output from display() should be:

BIO201
Lab course
4.0 credits
Lab fee is $50
Total fee is $530.0

Write an application named UseCourse that prompts the user for course information. If the user enters a class in any of the following departments, create a LabCourse: BIO, CHM, CIS, or PHY. If the user enters any other department, create a CollegeCourse that does not include the lab fee. Then display the course data.

Answer 1

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import java.util.*;

public class CollegeCourse {

    // attributes

    String dept;

    int id;

    double credits;

    double price;

    // constructor

    public CollegeCourse(String dept, int id, double credits){

        this.dept = dept;

        this.id = id;

        this.credits = credits;

    }

    // display()

    public void display(){

        System.out.println(dept+id+"\nNon-lab course\n"+credits+" credits");

        System.out.println("Total fee is $"+credits*120);

    }

}

LabCourse.java

import java.util.*;

public class LabCourse extends CollegeCourse{

    // attributes

    private double courseFee;

    // constructor

    public LabCourse(String dept, int id, double credits, double courseFee){

        super(dept, id, credits);

        this.courseFee = courseFee;

    }

    // override display()

    public void display(){

        System.out.println(dept+id+"\nLab course\n"+credits+" credits");

        System.out.println("Lab fee is $"+courseFee);

        System.out.println("Total fee is $"+((credits*120)+courseFee));

    }

}

UseCourse.java

import java.util.*;

public class UseCourse {

    public static void main(String[] args) {

        Scanner input = new Scanner(System.in);

        String dept, inStr;

        String[] labCourses = { "BIO", "CHM", "CIS", "PHY" };

        int id, credits;

        int found = 0;

        int x;

        System.out.print("Enter course: ");

        inStr = input.next();

        System.out.print("Enter id: ");

        id = input.nextInt();

        System.out.print("Enter credits: ");

        credits = input.nextInt();

        for(int i=0; i<labCourses.length; i++){

            if(inStr.equalsIgnoreCase(labCourses[i])){

                found = 1;

                break;

            }

        }

        if(found==1){

            LabCourse labCourse = new LabCourse(inStr, id, credits, 50);

            labCourse.display();

        }

        else{

            CollegeCourse collegeCourse = new CollegeCourse(inStr, id, credits);

            collegeCourse.display();

        }

    }

}