Question

Java Programming:

The following is my code:

import java.util.Arrays;

public class KWArrayList<E> {
   // Data fields
   /** The default initial capacity */
   private static final int INITIAL_CAPACITY = 10;
  
   /** The underlying data array */
   private E[] theData;
  
   /** The current size */
   private int size = 0;
  
   /** The current capacity */
   private int capacity = 0;
  
   @SuppressWarnings("unchecked")
   public KWArrayList() {
       capacity = INITIAL_CAPACITY;
       theData = (E[]) new Object[capacity];
   }  
  
   // A constructor for class KWArrayList<E> that accepts an integer argument
   // that represents the initial array capacity.
   @SuppressWarnings("unchecked")
   public KWArrayList(int num) {
       capacity = num;
       theData = (E[]) new Object[capacity];
   }      
  
   //Appends an item to the end of a KWArrayList
   public boolean add(E anEntry) {
       if (size == capacity) {
           reallocate();
       }
       theData[size] = anEntry;
       size++;
       return true;
   }
  
   // Insert an item at a specified position of index, i.e., theData[index]
   // Need to shift data in elements from index to size - 1
   public void add(int index, E anEntry) {
       if (index < 0 || index > size) {
           throw new ArrayIndexOutOfBoundsException(index);
       }
       if (size == capacity) {
           reallocate();
       }
       // Shift data in elements from index to size â€� 1
       for (int i = size; i > index; i--) {
           theData[i] = theData[i - 1];
       }
  
       // Insert the new item.
       theData[index] = anEntry;
       size++;
   }  
  
   public E get(int index) {
       if (index < 0 || index >= size) {
           throw new ArrayIndexOutOfBoundsException(index);
       }
       return theData[index];
   }
  
   public E set(int index, E newValue) {
  
       if (index < 0 || index >= size) {
           throw new ArrayIndexOutOfBoundsException(index);
       }

       E oldValue = theData[index];
       theData[index] = newValue;
       return oldValue;
   }  
  
   public E remove(int index) {
       if (index < 0 || index >= size) {
           throw new ArrayIndexOutOfBoundsException(index);
       }
      
       E returnValue = theData[index];
       for (int i = index + 1; i < size; i++) {
           theData[i - 1] = theData[i];
       }
      
       size--;
       return returnValue;
   }
  
   // Double the capacity of the array list
   private void reallocate() {
       capacity = 2 * capacity;
       theData = Arrays.copyOf(theData, capacity);
   }  
  
   // Get the size of the array list
   public int getSize() {
       return size;
   }
  
   // Get the capacity of the array list
   public int getCapacity() {
       return capacity;
   }  

public int indexOf(E value) {
       for(int index =0; index < size; index++) {
           if(value.equals(theData[index])) {
               return index;
           }
       }
       return -1;
   }  

\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

I need help implementing the following method:

2(b).
//   int remove(E value)
//   Searches for value and remove the item (that is equal to the value) of the
//   first occurrence and return the item's index,
//   or return -1 if cannot find an item that is equal to the value in the arrayList
//   Hint: you can use two methods in the KWArrayList class to complete the
//   removing and index returning operations described in the remove(E value) method
   public int remove(E value) {
      
       return -1;
   }
}      

Answer 1

Explanation:

Code in JAVA is given below

Output is given at the end

Code in JAVA:

KWArrayList.java Code

import java.util.Arrays;

public class KWArrayList<E> {

// Data fields

/** The default initial capacity */

private static final int INITIAL_CAPACITY = 10;

/** The underlying data array */

private E[] theData;

/** The current size */

private int size = 0;

/** The current capacity */

private int capacity = 0;

@SuppressWarnings("unchecked")

public KWArrayList() {

capacity = INITIAL_CAPACITY;

theData = (E[]) new Object[capacity];

}  

// A constructor for class KWArrayList<E> that accepts an integer argument

// that represents the initial array capacity.

@SuppressWarnings("unchecked")

public KWArrayList(int num) {

capacity = num;

theData = (E[]) new Object[capacity];

}   

//Appends an item to the end of a KWArrayList

public boolean add(E anEntry) {

if (size == capacity) {

reallocate();

}

theData[size] = anEntry;

size++;

return true;

}

// Insert an item at a specified position of index, i.e., theData[index]

// Need to shift data in elements from index to size - 1

public void add(int index, E anEntry) {

if (index < 0 || index > size) {

throw new ArrayIndexOutOfBoundsException(index);

}

if (size == capacity) {

reallocate();

}

// Shift data in elements from index to size 1

for (int i = size; i > index; i--) {

theData[i] = theData[i - 1];

}

// Insert the new item.

theData[index] = anEntry;

size++;

}  

public E get(int index) {

if (index < 0 || index >= size) {

throw new ArrayIndexOutOfBoundsException(index);

}

return theData[index];

}

public E set(int index, E newValue) {

if (index < 0 || index >= size) {

throw new ArrayIndexOutOfBoundsException(index);

}

E oldValue = theData[index];

theData[index] = newValue;

return oldValue;

}  

public E remove(int index) {

if (index < 0 || index >= size) {

throw new ArrayIndexOutOfBoundsException(index);

}

E returnValue = theData[index];

for (int i = index + 1; i < size; i++) {

theData[i - 1] = theData[i];

}

size--;

return returnValue;

}

// Double the capacity of the array list

private void reallocate() {

capacity = 2 * capacity;

theData = Arrays.copyOf(theData, capacity);

}  

// Get the size of the array list

public int getSize() {

return size;

}

// Get the capacity of the array list

public int getCapacity() {

return capacity;

}  

public int indexOf(E value) {

for(int index =0; index < size; index++) {

if(value.equals(theData[index])) {

return index;

}

}

return -1;

}  

/*I need help implementing the following method:

2(b).

// int remove(E value)

// Searches for value and remove the item (that is equal to the value) of the

// first occurrence and return the item's index,

// or return -1 if cannot find an item that is equal to the value in the arrayList

// Hint: you can use two methods in the KWArrayList class to complete the

// removing and index returning operations described in the remove(E value) method*/

public int remove(E value) {

int index = this.indexOf(value);

if(index==-1){

return -1;

}

value = this.remove(index);

return index;

}

}

KWTester.java Code:

public class KWTester {

public static void main(String[] args) {

KWArrayList<Integer> myList = new KWArrayList<Integer>(5);

myList.add(12);

myList.add(9);

myList.add(78);

myList.add(0, 89);

myList.add(23);

myList.add(111);

System.out.println("Current List:");

for(int i=0;i<myList.getSize();i++){

System.out.print(myList.get(i)+" ");

}

System.out.println();

System.out.println("\nTrying to remove value 89.");

Integer v = new Integer(89);

int index = myList.remove(v);

System.out.println("\nAfter removal of 89 List:");

for(int i=0;i<myList.getSize();i++){

System.out.print(myList.get(i)+" ");

}

}

}

OUTPUT:

Current List:

89 12 9 78 23 111

Trying to remove value 89.

After removal of 89 List:

12 9 78 23 111

Please provide the feedback!!

Thank You!