⚠️ Java Exception Handling

? Quick Overview

Exception Handling in Java is a powerful mechanism that allows a program to handle runtime errors gracefully. Instead of crashing the program, Java provides structured ways to detect, catch, and respond to unexpected situations.

? Key Concepts

An exception is an abnormal event that disrupts normal program flow
Exceptions occur at runtime
Java uses try, catch, finally, throw, and throws
All exceptions are part of the Throwable hierarchy

? Syntax & Theory

Java wraps risky code inside a try block and handles errors using one or more catch blocks. Optional cleanup code goes inside finally.

? View Code Example

// Basic try-catch syntax in Java
try {
int a = 10;
int b = 0;
int result = a / b;
System.out.println(result);
} catch (ArithmeticException e) {
System.out.println("Cannot divide by zero");
}

?️ Interactive Lab: Exception Simulator

Enter two numbers to simulate Java's ArithmeticException handling.
Try entering 0 as the second number!

int result = / ;

// Console output awaiting execution...

? Code Example

? View Code Example

// Handling an exception with finally block
try {
int[] nums = {1, 2, 3};
System.out.println(nums[5]);
} catch (ArrayIndexOutOfBoundsException e) {
System.out.println("Index out of range");
} finally {
System.out.println("Execution completed");
}

? Live Output / Explanation

When an exception occurs, Java immediately transfers control to the matching catch block. The finally block always executes, whether an exception occurs or not.

? Tips & Best Practices

Always catch specific exceptions instead of generic ones
Use finally for cleanup code like closing files
Never suppress exceptions silently
Keep try blocks small and focused

? Try It Yourself

Modify code to handle NullPointerException
Add multiple catch blocks
Remove the exception and observe normal flow
Create your own custom exception class