-- Add an example for Nullsafe Operator

Author: wmdev0808

README.md

@@ -2,3 +2,4 @@
 
 - [PHP For Beginners](challenge-001/README.md)
 - [Object-Oriented Principles in PHP](challenge-002/README.md)
+- [PHP 8 Crash Course](challenge-003/README.md)

challenge-003/02.php

@@ -0,0 +1,27 @@
+<?php
+
+class User {
+    public function profile()
+    {
+        // return new Profile;     
+        return null;   
+    }
+}
+
+class Profile {
+    public function employment()
+    {
+        return 'web developer';
+    }
+}
+
+$user = new User;
+
+// $profile = $user->profile();
+
+// if ($profile) {
+//     echo $profile->employment();
+// }
+
+// var_dump($user->profile()?->employment()); // NULL
+echo $user->profile()?->employment() ?? 'Not provided';

challenge-003/README.md

@@ -0,0 +1,59 @@
+# PHP 8 Crash Course
+
+- PHP 8 is now officially available. As part of this new release, not only will you benefit from performance improvements - thanks to the new JIT compiler - but you'll also enjoy useful new operators and types, attributes, match expressions, and so much more.
+
+- If you're intrigued, hop in and we'll review everything you need to know.
+
+## 01. How to Install PHP 8
+
+- About
+
+  Before we can play around, of course we must first download PHP 8. At the time of this writing, PHP 8 is not yet officially out. As such, we'll tap a custom [Homebrew](http://brew.sh/) formula to make the installation process as painless as possible. Alternatively, you might consider using Docker or Vagrant to create an isolated environment for testing PHP 8.
+
+## 02. The Nullsafe Operator
+
+- About
+
+  First up on the agenda is the new [Nullsafe operator](https://wiki.php.net/rfc/nullsafe_operator). This operator - represented as a question mark - allows you to call a method on the result of any expression if it does not evaluate to null. It sounds confusing, but it really isn't. Let's have a look.
+
+## 03. Match Expressions
+
+- About
+
+  Switch statements in PHP are useful, yet clunky. Think of the new [match expression](https://wiki.php.net/rfc/match_expression_v2) in PHP 8 as an improved switch. It's far more terse and flexible than its counterpart.
+
+## 04. Constructor Property Promotion
+
+- About
+
+  Next up is [constructor property promotion](https://wiki.php.net/rfc/constructor_promotion), which allows you to remove much of the tedious class initialization boilerplate code that you likely write for every any that accepts a dependency.
+
+## 05. $object::class
+
+- About
+
+  This next one is a small, but useful addition to PHP 8 that received [unanimous support](https://wiki.php.net/rfc/class_name_literal_on_object) during the voting stage. You now have the ability to use `::class` directly on an object. The result will be functionally identical to the result of `get_class()`. In PHP 7 and below, this functionality was limited to the class, itself.
+
+## 06. Named Parameters
+
+- About
+
+  Next up, we have [named parameters](https://wiki.php.net/rfc/named_params). This new PHP 8 feature allows you to pass function arguments according to, not their order, but the parameter name, itself. Let's discuss the pros and cons of adopting named parameters/arguments in your own projects.
+
+## 07. New String Helpers
+
+- About
+
+  It took a global pandemic for PHP to finally add a `str_contains` helper function, but it's finally here (along with a few others). In this episode, we'll review `str_contains()`, `str_starts_with()`, and `str_ends_with()`.
+
+## 08. Weak Maps
+
+- About
+
+  Weak maps are effectively key value stores that allow for garbage collection. You won't reach for these often, but they're nonetheless an important tool to have in your belt.
+
+## 09. Union and Pseudo Types
+
+- About
+
+  Next up, we'll discuss PHP 8's support for union types, as well as a new catch-all `mixed` pseudo-type. We can now - without resorting to docblocks - specify that a method parameter may accept multiple types.