The following code causes an exception error: import java.io.BufferedReader; imp

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(4));
              
    }
}

How do I use a Try/Catch block so that the exception is caught and the program exits a bit more gracefully. Starting with the provided code again (without the Try/Catch block), what needs to be done to fix the code so that it runs correctly. That is to say, it should display the last item in the ArrayList.

Explanation / Answer

Since the element that you intend to print is not defined, it will throw the IndexOutOfBoundsException. Enclose the following code snippet in a try block:

System.out.println(myArr.get(4));

In the catch block, write the following code snippet to display the last element of the arraylist:

System.out.println(myArr.get(myArr.size() -1));

Final code:

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");
         try
         {
         System.out.println(myArr.get(4));
        }
        catch(IndexOutOfBoundsException e)
        {
          System.out.println("Will cause exception since you are accessing undefined position in the arraylist ");
          System.out.println("Printing the last element in the array list ");
          System.out.println(myArr.get(myArr.size() -1));
        }

              
     }
}

Output:

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