Finally block behavior in PHP - Mini Project: Build & Apply

Finally Block Behavior

📖 Scenario: Imagine you are writing a PHP script that processes a payment. You want to make sure that some cleanup code always runs, no matter if the payment succeeds or fails.

🎯 Goal: Build a PHP script that uses a try, catch, and finally block to handle an error and always run cleanup code.

📋 What You'll Learn

Create a variable $paymentStatus with the value 'pending'.

Create a variable $errorOccurred with the value true.

Use a try block that throws an Exception with the message 'Payment failed' if $errorOccurred is true.

Use a catch block to catch the Exception and set $paymentStatus to 'failed'.

Use a finally block to set $cleanupDone to true.

Print the values of $paymentStatus and $cleanupDone.

💡 Why This Matters

🌍 Real World

In real payment systems, you must always clean up resources like closing database connections or logging, even if an error happens.

💼 Career

Understanding exception handling and finally blocks is important for writing reliable PHP code in web development and backend services.

1

Create initial variables

Create a variable called $paymentStatus and set it to 'pending'. Also create a variable called $errorOccurred and set it to true.

PHP

$paymentStatus = '';
$errorOccurred = false;
# Your code here

Need a hint?

Use = to assign values to variables. Strings need quotes.

2

Add try, catch, and finally blocks

Add a try block that throws an Exception with the message 'Payment failed' if $errorOccurred is true. Add a catch block to catch the Exception and set $paymentStatus to 'failed'. Add a finally block that sets $cleanupDone to true.

PHP

<?php
$paymentStatus = 'pending';
$errorOccurred = true;

# Add try, catch, and finally blocks below

Need a hint?

Use throw new Exception('message') inside try. Catch with catch (Exception $e). Use finally for cleanup.

3

Print the results

Print the values of $paymentStatus and $cleanupDone using echo. Separate them with a space.

PHP

<?php
$paymentStatus = 'pending';
$errorOccurred = true;

try {
    if ($errorOccurred) {
        throw new Exception('Payment failed');
    }
    $paymentStatus = 'success';
} catch (Exception $e) {
    $paymentStatus = 'failed';
} finally {
    $cleanupDone = true;
}

# Print $paymentStatus and $cleanupDone separated by a space

Need a hint?

Use echo to print. Use . to join strings. Convert boolean to string with a ternary.

4

Test with no error

Change the value of $errorOccurred to false and run the same code again. Print the values of $paymentStatus and $cleanupDone separated by a space.

PHP

<?php
$paymentStatus = 'pending';
$errorOccurred = false;

# Use the same try, catch, finally blocks below

try {
    if ($errorOccurred) {
        throw new Exception('Payment failed');
    }
    $paymentStatus = 'success';
} catch (Exception $e) {
    $paymentStatus = 'failed';
} finally {
    $cleanupDone = true;
}

# Print $paymentStatus and $cleanupDone separated by a space

Need a hint?

Change $errorOccurred to false to avoid the exception.