public class A {public void funl () {System.out.println ("Al");}public class B extends A {@Overridepublic void funl () {super.fun1 () ;System.out.println ("B1");public void fun2 () {System.out.println ("B2");public class C extends B {@Overridepublic void funl () {System.out.println ("C1");

A class is a group of objects which have common properties. Inheritance is an OOP concept in which…

public class A { public void funl () ( System.out.println ("Al"); public class B extends A { @Override public void funl () { super.funl (); System.out.println ("B1"); public void fun2 () { System.out.println ("B2"); public class C extends B { @Override public void funl () { System.out.println ("C1");

public class A { public void funl () ( System.out.println ("Al"); public class B extends A { @Override public void funl () { super.funl (); System.out.println ("B1"); public void fun2 () { System.out.println ("B2"); public class C extends B { @Override public void funl () { System.out.println ("C1");

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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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 the following questions. class shape { protected int length, width; void set (int a, int b) { length width = 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 area i. Identify the output of the program above. Please show the tracing table.
Find the error(s) in the following class definition: public class TestClass private int value1; private int value2; public void TestClass(int num1, int num2) { value1= num1; value2 = num2; }
Consider the following skeletal C program: void fun1(void); /* prototype */void fun2(void); /* prototype */void fun3(void); /* prototype */void main() { int a, b, c; . . .}void fun1(void) { int b, c, d; . . .}void fun2(void) { int c, d, e; . . .}void fun3(void) { int d, e, f; . . .}Given the following calling sequences and assuming that dynamic scoping is used, whatvariables are visible during the execution of the last function? Include with each visible variablethe name of the function in which it was defined.a. main calls fun1; fun1 calls fun2; fun2 calls fun3.b. main calls fun1; fun1 calls fun3.c. main calls fun2; fun2 calls fun3; fun3 calls fun1.d. main calls fun3; fun3 calls fun1.e. main calls fun1; fun1 calls fun3; fun3 calls fun2. Consider the following program, written in JavaScript-like syntax: // main programvar x, y, z;function sub1() {var a, y, z;. . .}function sub2() { var a, b, z; . . .}function sub3() { var a, x, w; . . .}Given the following calling sequences and…
public class A{private int var1;public int f1() {...}public int f1(int n1) {...}public int f2(int n1) {...}};public class B extends A{private int var2;public int f1(int n1) {...}public int f3() {...}}; -------------------------------- public class Tester{public static void main(String [] args){A a = new A();B b = new B();int num1 = b.f1(); //Statement 1int num2 = b.f2(22); //Statement 2int num3 = b.var2; //Statement 3a = new B(); //Statement 4}} ------------------------------------------------- Explain how a call in object b could possibly affect the value of A::var1.
Consider the following class declarations in C++:class C {protected: int x;public: void f(){...};};class C1: public C {protected: int x1;public: void h(C *obj){...};};class C2: public C1 {public: int x2;};class C3: public C {public: f(){...};};i. Draw the class hierarchyii. Assume that main contains the following declaration:C1 obj1;For each of the following expressions, say whether it is allowed in the code of main or not (they can be forbidden either because they violate the classdefinition or the protection mechanism)obj1.x , obj1.f() , obj1.x1 , obj1.x2iii. Assume that the body ofC1::h contains the following declarationsC2 *obj2;C3 *obj3;For each of the following expressions, say whether it is allowed in the bodyofC1::hor notobj->x , obj2->x , obj3->xiv. Assume that the body ofC1::h contains the following statementobj->f();Assume that we call C1::h with a parameter (pointing to an object) of classAnd what would be the method executed if f were declared virtual in C?
The Temperature class is an abstract class with two abstract methods. Create the Conversion class which inherits from Temperature. Use the formulas below to help with the temperature conversions. CODE: abstract class Temperature { public abstract double celsius(double temp); public abstract double fahrenheit(double temp);} //add class definitions below this line //add class definitions above this line public class Exercise3 { public static void main(String[] args) { //add code below this line Conversion c = new Conversion(); //add code above this line }}
Find the error in the following code segment: 1 2 |/ Superclass 3 public abstract class Vehicle 4- { public abstract double getKMPerlitre(); 7 (Other methods . . .) 8 } 10 11 12 // Subclass 13 public class Car extends Vehicle 14- { 15 private int distance; 16 public int getKMPerlitre() { return distance; } 17 18- 19 20 21 22 (Other methods .) 23 } 24 a. public abstract double getKMPerLitre(); should not end with a semicolon. O b. The getKMPerLitre method in the Car class should return a double. O c. The Car class cannot extend Vehicle class. O d. The Vehicle class should not be abstract.
methode code below abstract class Method { // declaration of variables protected int input; protected String output; // Abstract methods public abstract boolean isHard(); public abstract String specificWay(); public abstract void Method(); public abstract void Method(int input, String output); // Getter methods for the input field public int getInput() { return this.input; } // Setter methods for the input field public void setInput(int input) { this.input = input; } // Getter methods for the output field public String getOutput() { return this.output; } // Setter methods for the output field public void setOutput(String output) { this.output = output; } // Custom string representation of the object public String toString() { return "Method"; }}
Consider the following classes Package p1; Package p2; Package p2; Package p1; public class C1{ public class C2{ public class C3 { public class C4 extends C3{ public double age3; private String name; protected double salary; String major; void find(X void serach(){ void claculate(){ void compute(){ a) What are the methods that can access the variable age. b) What are the methods that can access the variable name. c) What are the methods that can access the variable salary. d) What are the methods that can access the variable major
public class Cylinder { public void smoothen() { } } } public abstract class Vessel implements Steerable { private Engine e; } System.out.println("Smoothening.."); public Engine getEngine() { return e; } public void setEngine (Engine e) { this.e = e; } public abstract void turnOn(); public class Engine { private Cylinder [] y; private int cyls = 1; static final int maxCylinders = 12; public void addCylinder (Cylinder y) { if (cyls
Finish the constructor for the KickBall class. public class Ball { public double diameter; public Ball(double diam) { diameter = diam; public class KickBall extends Ball private Color ballColor; public KickBall(double diam, Color ballColor) {