Which versions of PHP have you worked with?

Worked with PHP versions from 5.3 to the current 8.3. Started with PHP 5.3, actively used 5.6, 7.x. Currently, I actively work with 8.1, 8.2, and 8.3.

PHP 7 brought significant performance improvements thanks to the new Zend Engine 3, as well as a number of new features such as scalar types, return type declarations, null coalescing operator.

PHP 8 added features like named arguments, union types, match expression, attributes, JIT.

I paid special attention to migrating projects between different versions, considering syntax changes, deprecated functions, and innovations.

Main versions I worked with and their key features:

Version	Key features
5.x	OOP, namespaces, traits, generators
7.x	Performance improvements, scalar types, return types, null coalescing operator
8.x	Named arguments, union types, match expression, attributes, JIT

<?php
// Example of using scalar types in PHP 7+
function addNumbers(int $a, int $b): int {
    return $a + $b;
}

// Example of using null coalescing operator in PHP 7+
$name = $_GET['name'] ?? 'Guest';

// Example of using union types in PHP 8+
function processValue(int|float $value): void {
    // ... processing int or float
}

// Example of using match expression in PHP 8+
$status = 200;
$message = match ($status) {
    200 => 'OK',
    404 => 'Not Found',
    500 => 'Internal Server Error',
    default => 'Unknown status',
};

I consider the features of each version during development, try to use the current language capabilities where appropriate, and maintain backward compatibility when working with legacy code.