Consider an online holiday booking system. The users can register to book a holiday package. Currently, the design model includes the classes: User and Booking. Assume the class, Group_Booking, is a sub-class of the class, Booking. Which of the following cannot be inherited by the Group_Booking class in the object-oriented design? Select one: O a. The protected attributes of the Booking class O b. The protected methods of the Booking class O c. The constructors of the Booking class Od. The public methods of the Booking class

Consider an online holiday booking system. The users can register to book a holiday package. Currently, the design model includes the classes: User and Booking. Assume the class, Group_Booking, is a sub-class of the class, Booking. Which of the following cannot be inherited by the Group_Booking class in the object-oriented design? Select one: O a. The protected attributes of the Booking class O b. The protected methods of the Booking class O c. The constructors of the Booking class Od. The public methods of the Booking class

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

Which (if any) of the following conditions are necessary for using polymorphism? Select all correct answers. The classes involved are in the same hierarchy. None of the classes can be abstract. All of the subclasses involved override the same method. The object reference cannot be of an interface type. An object reference of the superclass is used to call any methods. A superclass object is referenced by a subclass reference. Which of the following (if any) are true of abstract methods? Select all correct answers. Abstract methods must have a method body. Abstract methods cannot be declared in a class that isn't abstract itself. Abstract methods cannot be private or static. Abstract methods can only be declared in an interface. Abstract methods cannot be called.
What does the super keyword represents and where can it be used? Give an example of a superclass and subclass. Be sure to make all the instances variables of the super class private. Include at least one constructor in each class and ensure that the constructor of the subclass calls the constructor of the superclass. Also include a toString method in both classes that returns the values of the instance variables with appropriate labels. Ensure that the toString method of subclass calls the toString method of the superclass so that the string returned contains the values of all the inherited instance variables.
Now we are going to use the design pattern for collecting objects. We are going to create two classes, a class AmazonOrder that models Amazon orders and a class Item that models items in Amazon orders. An item has a name and a price, and the name is unique. The Item class has a constructor that takes name and price, in that order. The class also has getters and setters for the instance variables. This is the design pattern for managing properties of objects. The setName() method should do nothing if the parameter is the empty string, and the setPrice() method should do nothing if the parameter is not positive. The class also has a toString() method that returns a string representation for the item in the format “Item[Name:iPad,Price:399.99]”. For simplicity, we assume an Amazon order can have at most 5 items, and class AmazonOrder has two instance variables, an array of Item with a length of 5 and an integer numOfItems to keep track of the number of items in the…
This is the question - Create an abstract NewspaperSubscription class with fields for the subscriber name, address, and rate. Include get and set methods for the name field and get methods for the address and subscription rate; the setAddress() method is abstract. Create two subclasses named PhysicalNewspaperSubscription and OnlineNewspaperSubscription. The parameter for the setAddress() method of the PhysicalNewspaperSubscription class must contain at least one digit; otherwise, an error message is displayed and the subscription rate is set to 0. If the address is valid, the subscription rate is assigned $15. The parameter for the setAddress() method of the OnlineNewspaperSubscription class must contain an at sign (@) or an error message is displayed. If the address is valid, the subscription rate is assigned $9. Code I was given - public class DemoSubscriptions { public static void main(String args[]) { PhysicalNewspaperSubscription pnsGood = new…
Consider an online holiday booking system. The initial design model contains the classes, Booking, Individual_Booking and Group_Booking via inheritance. Which of the following is used to describe the relationship of the three classes in the object-oriented design? a. The has-a relationship b. The get-a relationship c. The set-a relationship d. The is-a relationship
Write a class named Employee which implements Comparable Interface with name and salary as data field. Add a constructor with argument name and salary. Add getter and Setter for name and salary. Add CompareTo() method for the data Name. Write a class named Manager which inherits the Employee class. Add an instance variable, named department, of type String. Add a constructor in the subclass class with arguments name, salary, department and a toString() method that prints the manager’s name, department, and salary [Hint: Add a toString( ) method in the super class as well] Create 3 objects of Manager with following arguments 1. (Zayed, 500), 2. ( Ahmed, 700) 3. ( Faisal, 600) Create an Array object Add the above 3 objects into an Array object and Sort by Name and Display Create an object Employee class with argument (Zayed, 500, IT) Display the 1. Name 2. Salary 3. Department by using tostring() method.
We have two classes, Person and Employee. Both have a field, firstName. We have instances of these objectsPerson p and Employee e. Both p and e have the same value for firstName, specifically, p.firstName = “joe”and e.firstName = “joe” Which of the following statements is necessarily true? Group of answer choices 1. p.equals(e) will return true because they contain the same firstName. 2. We don’t know if either class will have an equals method. 3. There is not enough information to tell what p.equals(e) will return. 4. p.equals(e) will return false but p == e will be true.
Which of the following is true about abstract classes? Note that if a class can be sub-classed, this simply means that it can be derived from. Abstract classes can only contain abstract methods. They cannot be sub-classed. Abstract classes cannot be instantiated, but they can be sub-classed. Abstract classes can only contain abstract methods. They can be sub-classed. Abstract classes can be instantiated, but they cannot be sub-classed. Can an interface ever contain method bodies (i.e. content between {})? Unknown Yes No Sometimes
Consider the above scenario, where Billing class has composition relationship with Doctor having private instance variables (docName, docID and docFee) and a public getDocID() method, Patient having private instance variables (pName, pID, pDisease), Medicine having private instance variables (medID, medName, medQty, medPrice), and MedicalTest having private instance variables (testID, testName, testPrice). In addition, each class shall have toString method to display its object state. Also define getDocInfo method in Billing class that shall return the doctor. Implement getPaymentAmount() method in Billing class that shall return the total billing amount that includes doctor fee, medicine cost and medical tests fee. Considering the above scenario, write code that shall perform the following in the driver/test class: Get an amount from user. Traverse the ArrayList<Billing> using enhanced for loop. Print the billing details of those bills having total billing amount greater or…
1) Change the visibility of the variables and constructor in the Employee class to be more secure 2) Add an Admin class with the following features: a) The Admin class is a child of the Employee class b) Admin objects have an instance string password variable c) The Admin class has a 4 parameter constructor. One parameter sets the string, the other three parameters are used as arguments for a parent constructor call. d) Admin objects have an instance getInformation() method with a void return and an Employee object parameter. The method will request the calling Admin’s password and check user input. If input matches the password, the method will display the information of the Employee parameter Please use ***C Sharp** Language to answer the code
Q2. Write a program (Abstract+Interface) Define a class named Point containing: Two private instance variables x and y of type int. A full parametrized constructor Getters for all instance variables Define an abstract class named Shape containing: An instance variable named s of type Point. A full parametrized constructor A method named getS that returns the value of instance variable An abstract method named Area that has a return type double. Define an interface named Printable containing a method print without parameters and returning void. Define a class named Rectangle which is extended from class Shape, implements the interface printable and containing: Three instance variables named Length, Width of type int and an instance variable named d of type Point. A constructor with two parameters of type Point which initializes all the instance variables. The lengthis the difference in y-coordinates of any top and bottom point. length= Math.abs(s.getY()-d.getY()); The…
Problem B Now we are going to use the design pattern for collecting objects. We are going to create two classes, a class AmazonOrder that models Amazon orders and a class Item that models items in Amazon orders. An item has a name and a price, and the name is unique. The Item class has a constructor that takes name and price, in that order. The class also has getters and setters for the instance variables. This is the design pattern for managing properties of objects. The setName() method should do nothing if the parameter is the empty string, and the setPrice() method should do nothing if the parameter is not positive. The class also has a toString() method that returns a string representation for the item in the format “Item[Name:iPad,Price:399.99]”. For simplicity, we assume an Amazon order can have at most 5 items, and class AmazonOrder has two instance variables, an array of Item with a length of 5 and an integer numOfItems to keep track of the number of items in the…