Inheritance is a mechanismin which one class acquires the property of an other class.For example, a child inherits the traits of his/her parents.(a)Understand the program code below in Figure 1 and answer thefollowing questions.class shape {protected int length, width;void set (int a, int b) {lengthwidth = b; }void show ()= a;{System.out.println (length+" "+width); }}class rectangle extends shape {int area;void setArea () {area= length*width;}void show (){ System.out.println (area); }}class AreaRec{public static void main (String [] args){ rectangle r= new rectangle () ;r. Set (4,10);r. Show () ;r. SetArea () ;r. Show () ; }}Figure 1: Rectangle areai.Identify the output of the program above. Please show thetracing table.

let dry run Code by Comment class Shape{ protected int length, width; void set (int a, int b)…

Inheritance is a mechanismin which one class acquires the property of an other class. For example, a child inherits the traits of his/her parents. Understand the program code below in Figure 1 and answer the (a) following questions. class shape { protected int length, width; void set (int a, int b) { length = a; width = b; } void show () { System.out.println (length+" "+width); }} class rectangle extends shape { int area; void setArea () { area= length*width;} void show () { System.out.println (area); }} class AreaRec{ public static void main (String [] args) { rectangle r= new rectangle () ; r. Set (4,10) ; r. Show () ; r. SetArea (); r.Show () ;}} Figure 1: Rectangle area i. tracing table. Identify the output of the program above. Please show the

Inheritance is a mechanismin which one class acquires the property of an other class. For example, a child inherits the traits of his/her parents. Understand the program code below in Figure 1 and answer the (a) following questions. class shape { protected int length, width; void set (int a, int b) { length = a; width = b; } void show () { System.out.println (length+" "+width); }} class rectangle extends shape { int area; void setArea () { area= length*width;} void show () { System.out.println (area); }} class AreaRec{ public static void main (String [] args) { rectangle r= new rectangle () ; r. Set (4,10) ; r. Show () ; r. SetArea (); r.Show () ;}} Figure 1: Rectangle area i. tracing table. Identify the output of the program above. Please show the

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

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class Point { private: int x, y ; public: : x(u), y(v) {} Point (int u, int v) int getX) { return x; } int getY () { return y; } void doubleVal() { *= 2: y *= 2; } }; int main () { const Point myPoint (5, 3) myPoint.doubleVal() ; cout << myPoint.getX() << " " return 0; << myPoint.getY() << "\n"; }
toString() and equals() Methods This lab will demonstrate how the toString() and equals() methods work when they are not overridden. Type up the code and submit the BOTH results. CODE public class ObjectToString( public static void main(String[] args) { ClassOne co new ClassOne(); ClassTwo ct = new ClassTwo(); } } public class Classone { System.out.println(co); System.out.println(ct); System.out.println(co.equals(ct)); public void printfle() { System.out.println("I am from ClassOne"); } public class ClassTwo ( public void printMe() { } System.out.println("I am from ClassTwo"); Run the program and notice the output.
26. Assume the declaration of Exercise 24. A. Write the statements that derive the class dummyClass from class base as a private inheritance. (2 lines are { and }.) "A1 is { "A2 is "A3 is )) B. Determine which members of class base are private, protected, and public in class dummyClass. "B1 is dummyClass is a de
class implementation file -- Rectangle.cpp class Rectangle { #include #include "Rectangle.h" using namespace std; private: double width; double length; public: void setWidth (double); void setLength (double) ; double getWidth() const; double getLength() const; double getArea () const; } ; // set the width of the rectangle void Rectangle::setWidth (double w) { width = w; } // set the length of the rectangle void Rectangle::setLength (double l) { length l; //get the width of the rectangle double Rectangle::getWidth() const { return width; // more member functions here
public class Pet { protected String name; protected int age; public void setName(String userName) { name = userName; } public String getName() { return name; } public void setAge(int userAge) { age = userAge; } public int getAge() { return age; } public void printInfo() { System.out.println("Pet Information: "); System.out.println(" Name: " + name); System.out.println(" Age: " + age); } } import java.util.Scanner;public class PetInformation { public static void main(String[] args) { Scanner scnr = new Scanner(System.in); Pet myPet = new Pet(); Cat myCat = new Cat(); String petName, catName, catBreed; int petAge, catAge; petName = scnr.nextLine(); petAge = scnr.nextInt(); scnr.nextLine(); catName = scnr.nextLine(); catAge = scnr.nextInt(); scnr.nextLine(); catBreed = scnr.nextLine(); // TODO: Create generic pet (using petName, petAge) and then…
Take a look at the class declaration below: package p1; class Test8{ package p2; import p1.Test8; package p3; import p1.Test8; import p2.Test9; int i; class Test9 extends Test8 { private int j; protected int k; public int I; } class TestDemo3{ public static void main(String args[]){ Test8 t8 = new Test8(); Test9 t9 = new Test9(); } Out of these 4 variables declared in Test8, which are accessible in Test9 directly and by creating Test8 reference? In TestDemo3 main function, which variables can be used by each of the references t8 and t9?
public class StairViewer public static void main(String(] args) // Step 2: Create a rectangle and draw it as the // top step of the stair // location: (20, 10) // size: (20, 20) 18 // Step 3: Create a rectangle and draw it as the 19 // middle step of the stair 20 // location: below the top step, aligned on left // size: (40, 20) 21 22 23 24 // Step 4: Create a rectangle and draw it as the 25 // bottom step of the stair 26 // location: below the middle step, aligned on left // size: (60, 20) 27 28 29 30 } 31 32
Q 1: Access class members from the same package Note: ClassA and ClassB in this question are in the same package. public class ClassB { public int x = 1; int y = 2; private int z =3; } public class ClassA { public static void main(String[] args) { ClassB cb = new ClassB(); // System.out.print(cb.x); /* 1 */ // System.out.print(cb.y); /* 2 */ // System.out.print(cb.z); /* 3 */ } } 1.1- Which statement(s) are true? Choose all that apply. a. If statement 1 is uncommented, the code prints "1" to the output. b. If statement 2 is uncommented, the code prints "2" to the output. c. If statement 3 is uncommented, the code prints "3" to the output. .d. This code does not compile 1.2- Try to do the following: • Declare a character type variable myChar in the class ClassB, the variable myChar shouldn't be accessible through the object cb. Add a statement to the classA to test whether myChar is accessible.
public class LabProgram { public static void main(String args[]) { Course course = new Course(); String first; // first name String last; // last name double gpa; // grade point average first = "Henry"; last = "Cabot"; gpa = 3.5; course.addStudent(new Student(first, last, gpa)); // Add 1st student first = "Brenda"; last = "Stern"; gpa = 2.0; course.addStudent(new Student(first, last, gpa)); // Add 2nd student first = "Jane"; last = "Flynn"; gpa = 3.9; course.addStudent(new Student(first, last, gpa)); // Add 3rd student first = "Lynda"; last = "Robison"; gpa = 3.2; course.addStudent(new Student(first, last, gpa)); // Add 4th student course.printRoster(); } } // Class representing a student public class Student { private String first; // first name private String last; // last name private double gpa; // grade point average…
This is a subclass and doesn't has a main method yet. class Vector{Object items[];int length;int size; void Grow(){// Duplicate sizesize = size * 2; // Allocate new itemsObject new_items[] = new Object[size]; // Copy old itemsfor (int i = 0; i < length; i++)new_items[i] = items[i]; // Discard old itemsitems = new_items; // MessageSystem.out.println("Growing capacity to " + size + " elements");} public Vector(){size = 2;items = new Object[2];} public void Print(){// MessageSystem.out.println("Content:"); // Traversefor (int i = 0; i < length; i++)System.out.println(items[i]);} public void Insert(int index, Object item){// Check indexif (index < 0 || index > length){System.out.println("Invalid index");return;} // Grow if necessaryif (length == size)Grow(); // Shiftfor (int i = length - 1; i >= index; i--)items[i + 1] = items[i]; // Insertitems[index] = item; // One more itemlength++; // MessageSystem.out.println("Inserted " + item);} public void Add(Object…
For the following four classes, choose the correct relationship between each pair. public class Room ( private String m type; private double m area; // "Bedroom", "Dining room", etc. // in square feet public Room (String type, double area) m type type; m area = area; public class Person { private String m name; private int m age; public Person (String name, int age) m name = name; m age = age; public class LivingSSpace ( private String m address; private Room[] m rooms; private Person[] m occupants; private int m countRooms; private int m countoccupants; public LivingSpace (String address, int numRooms, int numoccupants) m address = address; new int [numRooms]; = new int [numOceupants]; m rooms %3D D occupants m countRooms = m countOccupants = 0; public void addRoom (String type, double area)
public class Father { public String name; public int age; // customer name Father(){ name=”Hassan”; age=50;} public void display(){ System.out.println(“Name:”+name); System.out.println(“Age:”+age); } } 1. Based on Figure 3, create a class named Child that inherits the Father class. Declare an instance name location (String) for class Child. 2. Define a constructor in class Child and give an appropriate initial values for the instance (name, age, location). 3. Define a method display () in class Child, execute the display ( ) method in superclass using the keyword super. Method display ( ) in class Child should print the information of name, age and location 4. Create other class named Main for the main method and create 2 objects for the 2 classes (Father and Child). Then execute the display ( ) method for Father and Child. Example of the output as in Figure 4: Father's info: Name: Josh Age: 50 Child's info: Name: Christy Age: 20 Location:…