Exam Question:

Write a Java program that reads an integer from the user, divides it by zero, and handles the resulting exception using exception handling. Implement a method called divideByZero(int number) that takes an integer number as a parameter and attempts to divide it by zero. If a ArithmeticException occurs, the method should catch the exception and print "Cannot divide by zero!".

1. Write the Java method divideByZero(int number) that implements the division operation and exception handling.
2. In the main method, prompt the user to enter an integer, call the divideByZero method, and handle any exceptions.
3. Explain briefly the concept and necessity of exception handling in programming.

import java.util.Scanner;

public class ExceptionHandlingExample {

    public static void divideByZero(int number) {
        try {
            int result = number / 0;
            System.out.println("Result: " + result);
        } catch (ArithmeticException e) {
            System.out.println("Cannot divide by zero!");
        }
    }

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.print("Enter an integer: ");
        int number = scanner.nextInt();
        divideByZero(number);
    }
}

Step-by-Step Explanation:

1. The method divideByZero(int number) is defined to handle the division operation and exception. Inside the try block, we attempt to divide the number by zero, which will result in an ArithmeticException. If this exception occurs, the catch block catches it and prints "Cannot divide by zero!".

2. In the main method, a Scanner object scanner is created to read user input. The user is prompted to enter an integer using the System.out.print statement. Then, nextInt() method is called on the scanner object to read the entered integer and store it in the number variable.

3. Finally, the divideByZero(number) method is called, passing the entered number as an argument. This method handles the division by zero exception and prints the appropriate message.

Concept and Necessity of Exception Handling:

Exception handling is a mechanism in programming that allows for the graceful handling of runtime errors or exceptional situations. These situations can occur due to various reasons, such as input errors, file I/O issues, network failures, or divide by zero operations.

Exceptions provide a way to transfer control from one part of the program to another when an exceptional condition arises. By handling exceptions, developers can prevent the program from crashing or abruptly terminating, improving the program's reliability and user experience.

Exception handling typically involves the use of try-catch blocks. The code that may raise an exception is enclosed within the try block, and any potential exceptions are caught and handled in the catch block. This separation allows for more controlled flow of the program and better error reporting.

In our example, the necessity of exception handling is evident when dividing by zero. Without exception handling, the program would terminate abruptly with a ArithmeticException. However, by using exception handling, we catch the exception and gracefully handle it by displaying a user-friendly error message instead.