Q

[Object Oriented Programming]

Which one of the given exceptions is raised when a user enters a String literal "hello" during execution of the following code?

import java.util.*;
class Message
{
    public void doIt()
    {
        System.out.println("Enter a message");
        int s = (new Scanner(System.in)).nextInt();
        System.out.println(s);
    }
}

Step-by-Step Explanation:

Step 1: Understanding the Code

The program uses the Scanner class to take input from the user:

The method nextInt() expects an input of type integer.

Step 2: What User Inputs?

The user enters:

This is a String, not an integer.

Step 3: What Happens Internally?

• nextInt() tries to convert input into an integer
• But "hello" cannot be converted to a number
• So Java throws an exception

Which Exception is Thrown?

The Scanner class throws:

when the input does not match the expected data type.

Why Other Options are Incorrect?

• InputFormatException → Not a standard Java exception
• NullPointerException → Occurs when accessing null reference, not input mismatch
• NumberFormatException → Occurs when manually converting string to number (e.g., Integer.parseInt()), not with Scanner.nextInt()

Important Note:

Exception behavior differs based on method used:

Conclusion:

Since nextInt() receives invalid (non-integer) input, Java throws:

Therefore, the correct answer is: (a)