Question

Consider the following code snippet:

public class ExceptionHandlingExample {
    public static void main(String[] args) {
        try {
            String str = "Hello";
            int num = Integer.parseInt(str);
            System.out.println("The number is " + num);
        } catch (NumberFormatException e) {
            System.out.println("Invalid number format");
        } catch (Exception e) {
            System.out.println("An error occurred");
        }
    }
}

Explain what will be the output of running this code snippet and why. Additionally, explain the purpose of exception handling in Java and why it is important for programmers to handle exceptions properly.

Answer

The output of running this code will be:

Invalid number format

The purpose of exception handling in Java is to handle and manage errors or exceptional conditions that may occur during the execution of a program. Exceptions are events that disrupt the normal flow of the program and need to be handled in order to prevent the program from crashing or producing incorrect results.

In the given code snippet, the parseInt() method is called to convert the string "Hello" into an integer. However, since "Hello" cannot be converted into a valid integer, a NumberFormatException is thrown.

The code includes a try-catch block to handle this exception. The first catch block catches the NumberFormatException and prints "Invalid number format". If the code did not include this catch block, the program would terminate abruptly and an error message would be displayed to the user.

The second catch block, which catches the more general Exception class, is not executed in this scenario because the NumberFormatException is already caught and handled in the previous catch block.

It is important for programmers to handle exceptions properly to ensure the robustness and reliability of their programs. By handling exceptions, programmers can gracefully handle unexpected situations and provide appropriate error messages to users. Proper exception handling also helps in troubleshooting and debugging the code by providing information about the cause of errors.