Computers And Technology College

QUESTIONS / TASKS • Which class is the superclass? Which is the subclass? What does it mean that the Cat class extends the Animal class? • The Cat class cannot directly access the fields it inherits from Animal. Why not? • The subclass constructor typically calls the superclass constructor to initialize the inherited fields. Write a constructor for the Cat class above. It should take as parameters the cat’s name and a boolean indicating whether it is short-haired, and it should call the superclass constructor to initialize the inherited fields. Update the test program to create an instance of class Cat. Cat c = new Cat("Kitty", false); • To manipulate the inherited fields, the subclass can use the inherited accessor and mutator methods. Write a toString method for the Cat class above. It should return a string consisting of the cat’s name followed by either " (short-haired)" or " (long-haired)". Update the test program to test your method. System.out.println( c ); • The subclass can override an inherited method, replacing it with a version that is more appropriate. Write an isSleeping method for the Cat class. It should reflect the fact that cats seem to sleep all of the time! Update the test program to test your method.

Answers

Answer 1

1. `Animal` is the superclass, and `Cat` is the subclass, signifying inheritance.

2. Private fields in `Animal` can't be directly accessed in `Cat`.

3. Created a `Cat` constructor and updated the test program.

4. Added a `toString` method for `Cat` and updated the test program.

5. Implemented an `isSleeping` method for `Cat` and updated the test program.

(Given in the attachment)

The question probable maybe:

PROGRAM

Consider the Animal and Cat classes in the following Java source code files. SAVE ALL 3.

*Animal.java

*A simple class representing an animal.

public class Animal {

private String name;

private int numLegs:

public Animal (String name, int numLegs) {

this.name name;

this.numlegs = numLegs;

}

public String getName() {

return this.name;

}

public int getNumLegs() {

return this.numLegs;

}

public boolean isSleeping(int hour, int minute) (

if (hour> 24 || hour <0 || minute> 60 || minute < 0) {

throw new IllegalArgumentException("invalid time

specified");

}

return (hour > 22 || hour <= 5)

}

public String toString() {

return this.name;

}

public static void printAnimalName (Animal an) (

// Output the name of the animal
System.out.println( an );

}

*Cat.java

*A simple class represting a cat.

public class Cat extends Animal {

private boolean isShortHaired;

public Cat() {

super ("Mycatt", 3);

}

public boolean isShortHaired() {

return this.isShorthaired;

}

public boolean isExtroverted() {

return false;

}

*testDriver.java

* A simple test program for the Animal class

public class testDriver {

public static void main (String [] argv) {

}

QUESTIONS / TASKS •
1. Which class is the superclass? Which is the subclass? What does it mean that the Cat class extends the Animal class?

2. The Cat class cannot directly access the fields it inherits from Animal. Why not?

3. The subclass constructor typically calls the superclass constructor to initialize the inherited fields. Write a constructor for the Cat class above. It should take as parameters the cat’s name and a boolean indicating whether it is short-haired, and it should call the superclass constructor to initialize the inherited fields.

Update the test program to create an instance of class Cat.

Cat c = new Cat("Kitty", false);

4. To manipulate the inherited fields, the subclass can use the inherited accessor and mutator methods. Write a toString method for the Cat class above. It should return a string consisting of the cat’s name followed by either " (short-haired)" or " (long-haired)".

Update the test program to test your method.

System.out.println( c );

5. The subclass can override an inherited method, replacing it with a version that is more appropriate. Write an isSleeping method for the Cat class. It should reflect the fact that cats seem to sleep all of the time!

Update the test program to test your method.

QUESTIONS / TASKS Which Class Is The Superclass? Which Is The Subclass? What Does It Mean That The Cat

Related Questions

Implement a Breadth-First Search of the people in the network who are reachable from person id 3980. You can implement BFS with a queue and the pseudocode is given in CLRS. Print out the distance (number of connections) from person 3980 to every person who is reachable from 3980 via edge traversals. Note that not all people in this network may be reachable via edge traversals from user id 3980, so users that are not accessible can be ignored in BFS.

Answers

Answer:

Check the explanation

Explanation:

import java.io.File;

import java.io.FileNotFoundException;

import java.util.LinkedList;

import java.util.Scanner;

import static org.junit.Assert.assertEquals;

/**

* CS146 Assignment 3 Node class This class is used for undirected graphs

* represented as adjacency lists The areFriends() method checks if two people

* are friends by checking if an edge exists between the two

public class NetworkAdjList {

// Initialize array with max number of vertices taken from SNAP

static int max_num_vertices = 88234;

static LinkedList<Integer>[] adjacencyList = new LinkedList[max_num_vertices];

public static void createAdjacencyList() {

// Initialize array elements

for (int j = 0; j < max_num_vertices; j++) {

adjacencyList[j] = new LinkedList<Integer>();

}

// Get file path of the 3980.edges file

String filePath = "C:\\Users\\shahd\\Documents\\CS146\\Assignment 3\\Question 3\\Question3\\src\\a3\\3980.edges";

File f = new File(filePath);

// Use Scanner to read edges from the file and put it into adjacency list

int a;

int b;

try {

Scanner fileIn = new Scanner(f);

while (fileIn.hasNext()) {

a = fileIn.nextInt();

b = fileIn.nextInt();

adjacencyList[a].add(b);

adjacencyList[b].add(a); // We need to add the edges both ways

}

} catch (FileNotFoundException e) {

e.printStackTrace();

}

public static boolean areFriends(int A, int B) {

// If the adjacency list contains (A, B) edge, then return true, else false

if (adjacencyList[A].contains(B)) {

return true;

} else {

return false;

}

private static void bfsHelper(boolean visited[], int currentNode, int dis, int sourceNode) {

dis++;

if(!visited[currentNode]) {

visited[currentNode] = true;

for(int neighbor: adjacencyList[currentNode]) {

System.out.println(neighbor + " is at a distance of " + dis + " from " + sourceNode);

bfsHelper(visited, neighbor, dis++, sourceNode);

}

public static void BFStraversal(int start) {

boolean visited[] = new boolean[max_num_vertices];

bfsHelper(visited, start, 0, start);

}

public static void main(String[] args) {

/**

* These test cases assume the file 3980.edges was used

createAdjacencyList();