Modern PHP tour: 5 to 8.4

PHP 5 OOP

PHP 5 turned PHP into an object language: classes, visibility, exceptions. Most legacy code you will meet was born here. Start the timeline at PHP 5 - the hub for the whole story is PHP versions.

class Post { public string $title; public function __construct(string $title) { $this->title = $title; } }

PHP 7 speed and types

PHP 7 doubled execution speed and added scalar type hints plus return types. Sloppy numeric code that relied on silent coercion started failing loudly - which was the point. See PHP 7.

function add(int $a, int $b): int { return $a + $b; }

PHP 8 expression power

PHP 8 made code expression-shaped: match, nullsafe calls, named arguments, attributes. Branches collapsed into values you can assign and return. Tour it via PHP 8 and PHP 8.0.

$label = match ($status) { "new" => "Fresh", "paid" => "Done", default => "Unknown", };

Upgrade path to 8.5

Jump one minor version at a time on a copy of the project: run the test suite, read the migration notes, fix deprecations before they become errors. The linters from the last lesson catch half of this work mechanically.

Next: PHP 8.5 for busy developers

Article author: Arthur Isaev