Try-Catch Block

What is a Try-Catch Block?

A try-catch block is used to handle exceptions gracefully in Java.

It allows you to run risky code in the try block, and catch any exceptions that may occur.

⚠️ It prevents the program from crashing and gives control to the developer on what to do if something goes wrong.

🔧 Syntax

try {
    // Code that might throw an exception
} catch (ExceptionType e) {
    // Code to handle the exception
}

✅ Example

public class Main {
    public static void main(String[] args) {
        int a = 10, b = 0;

        try {
            int result = a / b;
            System.out.println("Result: " + result);
        } catch (ArithmeticException e) {
            System.out.println("Error: Division by zero is not allowed.");
        }
    }
}

Error: Division by zero is not allowed.

🔁 Multiple Catch Blocks

You can handle different types of exceptions separately:

try {
    int[] arr = new int[3];
    System.out.println(arr[5]); // ArrayIndexOutOfBoundsException
} catch (ArithmeticException e) {
    System.out.println("Math error");
} catch (ArrayIndexOutOfBoundsException e) {
    System.out.println("Array index is invalid");
}

🧠 Java checks catch blocks from top to bottom, so always catch specific exceptions first.

🔄 Nested Try-Catch

You can also nest try-catch blocks to handle exceptions independently:

try {
    System.out.println("Outer try");
    try {
        int x = 5 / 0;
    } catch (ArithmeticException e) {
        System.out.println("Inner catch: Division by zero");
    }
} catch (Exception e) {
    System.out.println("Outer catch");
}

Outer try
Inner catch: Division by zero

🔍 Best Practices

• Catch the most specific exception first

• Use Exception only when you don’t know which one might occur

• Avoid empty catch blocks (catch(Exception e) {}) — always handle or log the exception

• Don’t use try-catch to control normal flow (not a substitute for if)

🧾 Recap