Module 8: Exception Handling

⚠️ What is an Exception?

An exception is an event that disrupts the normal flow of the program. It is an object which is thrown at runtime.

Exceptions in Java are handled using the try, catch, finally, and throw/throws keywords.

🧪 Basic Try-Catch Example

                    public class Main {
                        public static void main(String[] args) {
                            try {
                                int a = 10 / 0;
                            } catch (ArithmeticException e) {
                                System.out.println("Error: " + e.getMessage());
                            }
                        }
                    }
                    

🔁 Finally Block

The finally block always executes, even if an exception occurs.

                    try {
                        int[] arr = new int[3];
                        System.out.println(arr[5]);
                    } catch (ArrayIndexOutOfBoundsException e) {
                        System.out.println("Array error!");
                    } finally {
                        System.out.println("Cleanup code runs here.");
                    }
                    

📤 Throw & Throws

throw is used to explicitly throw an exception. throws is used to declare exceptions.

                    class Test {
                        static void checkAge(int age) throws Exception {
                            if (age < 18) {
                                throw new Exception("Not eligible to vote");
                            }
                        }
                    
                        public static void main(String[] args) {
                            try {
                                checkAge(16);
                            } catch (Exception e) {
                                System.out.println(e.getMessage());
                            }
                        }
                    }