Question

(I don't need code for this question I only need explanation how to solve the question.)

The following code causes an exception error:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;

public class Ex02 {

    public static void main(String[] args) throws IOException {

        BufferedReader userInput = new BufferedReader
            (new InputStreamReader(System.in));

        ArrayList<String> myArr = new ArrayList<String>();
        myArr.add("Zero");
        myArr.add("One");
        myArr.add("Two");
        myArr.add("Three");        
        System.out.println(myArr.get(7));
               
    }
}

Starting with this provided code, add the following functionality:

1. Use a Try/Catch block so that the exception is caught and the program exits a bit more gracefully. Save this file as TryCatch.java. (Be sure to rename the Public Class accordingly.)
2. Starting with the provided code again (without the Try/Catch block), fix the code so that it runs correctly. That is to say, it should display the last item in the ArrayList. Save this file as Fixed.java. (Be sure to rename the Public Class accordingly.)
3. (I don't need code for this question I only need explanation how to solve the question.)

Answer 1

Your code gives the error something like shown below;

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 7, Size: 4                                                             

        at java.util.ArrayList.rangeCheck(ArrayList.java:657)                                                                                 

        at java.util.ArrayList.get(ArrayList.java:433)                                                                                        

        at Main.main(Main.java:18)        

This error is due to myArr.get(7), the dynamic array is of size 4 as 4 values are added and accessing the 7th element throws exception of out of bounds

So, changing the statement will resolve the error. Eg. myArr.get(3) will print Three