Error vs Exception in PHP - Hands-On Comparison

Understanding Error vs Exception in PHP

📖 Scenario: Imagine you are building a simple PHP script that processes user input and performs division. Sometimes, the input might cause errors or exceptions. Understanding how PHP handles errors and exceptions helps you write safer code.

🎯 Goal: You will create a PHP script that demonstrates the difference between an error and an exception by triggering each and handling the exception properly.

📋 What You'll Learn

Create a variable called numerator with the value 10

Create a variable called denominator with the value 0

Use a try block to attempt division and throw an Exception if denominator is zero

Use a catch block to catch the Exception and print the exception message

Trigger a PHP error by calling an undefined function undefinedFunction()

Print the result of the division if no exception occurs

💡 Why This Matters

🌍 Real World

Handling errors and exceptions properly is important in real-world PHP applications to avoid crashes and provide clear feedback to users.

💼 Career

Understanding error vs exception handling is a key skill for PHP developers to write robust and maintainable code.

1

Set up numerator and denominator variables

Create a variable called numerator and set it to 10. Create another variable called denominator and set it to 0.

PHP

$numerator = 10;
$denominator = 0;
# Your code here

Need a hint?

Use $numerator = 10; and $denominator = 0; to create the variables.

2

Add try block to check denominator and throw Exception

Add a try block. Inside it, check if $denominator is zero. If yes, throw a new Exception with the message 'Cannot divide by zero.'. Otherwise, calculate the division and store it in $result.

PHP

<?php
$numerator = 10;
$denominator = 0;

try {
    # Your code here
}

Need a hint?

Use throw new Exception('Cannot divide by zero.'); inside the if condition.

3

Add catch block and trigger a PHP error

Add a catch block to catch the Exception as $e and print the exception message using echo. After the try-catch, call an undefined function undefinedFunction() to trigger a PHP error.

PHP

<?php
$numerator = 10;
$denominator = 0;

try {
    if ($denominator == 0) {
        throw new Exception('Cannot divide by zero.');
    }
    $result = $numerator / $denominator;
} catch (Exception $e) {
    # Your code here
}

# Trigger a PHP error below
# Your code here

Need a hint?

Use catch (Exception $e) and inside it echo "Exception caught: " . $e->getMessage();. Then call undefinedFunction(); outside the try-catch.

4

Print the division result if no exception

After the try-catch block, add a check to see if $result is set. If yes, print "Result: " followed by the value of $result.

PHP

getMessage() . "\n";
}

undefinedFunction();

# Your code here

Need a hint?

Use if (isset($result)) { echo "Result: " . $result; } to print the result only if it exists.