Added new exceptions page

assets/templates/_table_of_contents.phtml

@@ -22,6 +22,7 @@
         <li><a href="<?= page_path('static') ?>">Static</a></li>
         <li><a href="<?= page_path('interfaces') ?>">Interfaces</a></li>
         <li><a href="<?= page_path('abstract') ?>">Abstract Classes</a></li>
+        <li><a href="<?= page_path('exceptions') ?>">Exceptions</a></li>
     </ol>
     <a href="<?= page_path('credits') ?>">Credits</a>
 </div>

code/exceptions.php

@@ -0,0 +1,60 @@
+<?php
+
+// Sometimes things go wrong when someone uses your code. How do we handle this situation?
+// PHP has Exceptions to define errors and the ability to "throw" them to stop code
+// execution and tell the user of your code that something is wrong.
+class Processor
+{
+    public function charge($creditCard)
+    {
+        if (strlen($creditCard->getNumber()) !== 16) {
+            throw new Exception('Credit card is not right');
+        }
+    }
+}
+
+// In this case, if someone tried to use the Processor class
+// to charge a credit card number that is not 16 characters long, an
+// exception will be thrown which stops the rest of the code from running.
+$processor = new Processor();
+$processor->charge('1234');
+
+// A developer who wants to prevent an exception from stopping code execution
+// can catch the exception and use it for logging or a return an error to a user.
+
+// Just wrap the code that might throw an exception with the keyword "try" and brackets
+// followed by "catch", the exception type in parentheses and more brackets.
+try {
+    $processor->charge('1234');
+} catch (Exception $e) {
+    echo $e->getMessage() . "\n";
+}
+
+// You can make your own custom exceptions as well. They are just classes
+// that extend Exception.
+class MyCustomException extends Exception {}
+
+// Then, you can try to catch your exception instead of the base exception.
+try {
+    throw new MyCustomException('I am a custom exception');
+} catch (MyCustomException $e) {
+    echo "Cauth MyCustomException\n";
+}
+
+// Since all exceptions inherit from Exception, catching
+// Exception will catch any and all exceptions that might be thrown.
+try {
+    throw new MyCustomException('I inherit from Exception');
+} catch (Exception $e) {
+    echo "Still caught MyCustomException\n";
+}
+
+// You can also create multiple catch blocks to handle different types of exceptions in
+// one try-catch.
+try {
+    throw new MyCustomException('I am being thrown again');
+} catch (MyCustomException $e) {
+    echo "MyCustomException was caught\n";
+} catch (Exception $e) {
+    echo "Just in case a different exception is thrown\n";
+}

config.php

@@ -146,7 +146,13 @@ return [
         Page::create('abstract', null, 'abstract.php', [
             'title' => 'Abstract Classes',
             'subtitle' => 'Inheriting an interface',
-            'previous' => 'interfaces',
+            'previous' => 'interface',
+            'next' => 'exceptions',
+        ]),
+        Page::create('exceptions', null, 'exceptions.php', [
+            'title' => 'Exceptions',
+            'subtitle' => 'Throwing errors',
+            'previous' => 'abstract',
             'next' => '',
         ]),
     ],