Please add the following three methods to our ArrayList class (i.e. StringArrayList.java):

1.void clear(): This method is used to remove all the elements from any list.

2.int indexOf(String str): The method returns the first occurrence of a given element, or returns -1 in case the element is not on the list.

3.int lastIndexOf(String str): The method returns the last occurrence of a given element, or returns -1 in case the element is not on the list.

import java.util.Arrays;

public class StringArrayList implements myList{

private String[] theData;

private int size = 0;

//the number of elements in the current list

//the next position to add data

private int capacity = 0;

private static final int INITIAL_CAPACITY = 5;

public StringArrayList(){

theData = new String[INITIAL_CAPACITY];

capacity = INITIAL_CAPACITY;

}

@Override

public void add(String value) {

if(size>=capacity){

//full; create a new one

reallocate();

theData[size]=value;

size++;

}else{

theData[size]=value;

size++;

}

}

private void reallocate(){

capacity = capacity * 2;

theData = Arrays.copyOf(theData, capacity);

}

@Override

public void add(int index, String value) {

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

throw new

ArrayIndexOutOfBoundsException(index);

}

if(size>=capacity){

reallocate();

}

for(int i = size - 1; i >= index; i--){

theData[i+1] =theData[i];

}

theData[index] = value;

size++;

}

public interface myList { public void add(String value); public void add(int index, String value); public String remove(int index); public String get(int index); public String set(int index, String value); }

public class Test {

public static void main(String[] args) {

StringArrayList testList = new StringArrayList();

testList.add("Alice");

testList.add("Cher");

testList.add("David");

testList.add("Ellen");

testList.add(1,"Bob");

testList.add("Frank");

testList.remove(1);

testList.set(1, "Joseph");

testList.traverse();

System.out.println("The value at index 2 is " +

testList.get(2));

//testList.set(10, "Hugh");

}

}