Multiple catch blocks in PHP - Mini Project: Build & Apply

Handling Errors with Multiple Catch Blocks in PHP

📖 Scenario: Imagine you are writing a PHP script that processes user input for a simple calculator. The input might cause different types of errors, such as division by zero or invalid input format. You want to handle these errors gracefully using multiple catch blocks.

🎯 Goal: Build a PHP script that uses try and catch blocks to handle different exceptions separately. You will create a function that divides two numbers and catches DivisionByZeroError and TypeError with different messages.

📋 What You'll Learn

Create a function called divide that takes two parameters: $a and $b.

Inside the function, perform the division $a / $b inside a try block.

Use multiple catch blocks to handle DivisionByZeroError and TypeError exceptions separately.

Print different error messages for each exception type.

Call the divide function with different inputs to test the error handling.

💡 Why This Matters

🌍 Real World

Handling different errors separately helps make programs more reliable and user-friendly, especially when dealing with user input or external data.

💼 Career

Understanding multiple catch blocks is important for writing robust PHP applications that can gracefully handle various runtime errors.

1

Create the divide function with parameters

Write a PHP function called divide that takes two parameters: $a and $b. Inside the function, start a try block but do not add any code inside it yet.

PHP

<?php

function divide($a, $b) {
    try {
        // Your code here
    }
}

Need a hint?

Define the function with function divide($a, $b) and add a try block inside it.

2

Add division inside the try block

Inside the try block of the divide function, write code to return the result of $a / $b.

PHP

<?php

function divide($a, $b) {
    try {
        // Your code here
    }
}

Need a hint?

Use return $a / $b; inside the try block.

3

Add multiple catch blocks for error handling

Add two catch blocks after the try block in the divide function. The first catch should catch DivisionByZeroError and print "Error: Division by zero.". The second catch should catch TypeError and print "Error: Invalid input type.".

PHP

<?php

function divide($a, $b) {
    try {
        return $a / $b;
    } catch (DivisionByZeroError $e) {
        // Your code here
    } catch (TypeError $e) {
        // Your code here
    }
}

Need a hint?

Use two catch blocks: one for DivisionByZeroError and one for TypeError, each printing the correct message.

4

Call the divide function and print results

Call the divide function three times with these inputs: 10, 2, 5, 0, and "a", 3. Print the result or error message for each call on a new line using echo.

PHP

<?php

function divide($a, $b) {
    try {
        return $a / $b;
    } catch (DivisionByZeroError $e) {
        echo "Error: Division by zero.";
    } catch (TypeError $e) {
        echo "Error: Invalid input type.";
    }
}

// Your code here

Need a hint?

Call divide(10, 2), divide(5, 0), and divide("a", 3). Print each result followed by a newline.