finally block in exception handling

 

✅ The finally Block in Java

In Java, the finally block is used with try-catch to guarantee execution of a block of code regardless of whether an exception occurs or not. It's commonly used for cleanup operations such as closing files, releasing resources, or resetting values.

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🔹 Syntax of try-catch-finally

try {
    // Code that might throw an exception
} catch (ExceptionType e) {
    // Exception handling code
} finally {
    // Code that always executes
}

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📘 Example 1: Basic Use of finally

public class FinallyExample {
    public static void main(String[] args) {
        try {
            int data = 10 / 0; // ArithmeticException
        } catch (ArithmeticException e) {
            System.out.println("Caught exception: " + e.getMessage());
        } finally {
            System.out.println("Inside finally block – cleanup done.");
        }
    }
}

Output:

Caught exception: / by zero  
Inside finally block – cleanup done.

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📘 Example 2: No Exception Occurs

public class FinallyNoException {
    public static void main(String[] args) {
        try {
            int data = 10 / 2;
            System.out.println("Result: " + data);
        } catch (ArithmeticException e) {
            System.out.println("Exception caught");
        } finally {
            System.out.println("Finally block executed.");
        }
    }
}

Output:

Result: 5  
Finally block executed.

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📘 Example 3: Exiting Early with return

Even if you use return inside try or catch, the finally block will still run.

public class FinallyWithReturn {
    public static void main(String[] args) {
        System.out.println(testMethod());
    }

    static String testMethod() {
        try {
            return "Try block return";
        } catch (Exception e) {
            return "Catch block return";
        } finally {
            System.out.println("Finally block executed.");
        }
    }
}

Output:

Finally block executed.  
Try block return

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✅ Why use finally?

• To ensure critical code always executes.

• To release system resources, e.g., close database connections, file streams.

• To perform consistent cleanup regardless of program state.