PHP Modern

Modern PHP 8.x Development

Before writing code

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PHP 8.0 Features

Constructor Property Promotion

Declare and assign properties directly in the constructor signature — eliminates boilerplate. Heavily used in Magento service classes.

Named Arguments

Call functions with parameter names: array_slice(array: $arr, offset: 2). Improves readability for functions with many parameters.

Match Expressions

Type-safe switch replacement that returns a value. No fall-through, strict comparison. Better than switch for value mapping.

Union Types

int|string in parameter and return types. Allows multiple type declarations.

Nullsafe Operator

$obj?->method()?->property — short-circuits to null if any part is null. Replaces nested null checks.

Attributes

Native metadata annotations: #[Route('/path')], #[Override]. Replace docblock annotations with first-class language support.

PHP 8.1 Features

Enums

First-class enumerations — backed (string/int) and unit enums. Perfect for status codes, types, categories. Use backed enums for database/API values.

Readonly Properties

public readonly string $name — can only be set once (usually in constructor). Enforces immutability.

Fibers

Lightweight concurrency primitives — PHP-level coroutines. Foundation for async frameworks. Limited direct usage in Magento.

Intersection Types

TypeA&TypeB — value must satisfy ALL types. Useful for ensuring a parameter implements multiple interfaces.

First-class Callable Syntax

strlen(...) creates a Closure from a function. Cleaner than Closure::fromCallable('strlen').

PHP 8.2 Features

Readonly Classes

readonly class Dto { ... } — all properties are implicitly readonly. Perfect for Data Transfer Objects and value objects.

Deprecated: Dynamic Properties

Creating properties not declared in the class is deprecated. Magento core addressed this throughout — always declare properties.

Standalone Types

true, false, null as standalone types in declarations.

Constants in Traits

Traits can now define constants.

PHP 8.3 Features

Typed Class Constants

const string NAME = 'value'; — type-safe constants. Strengthens contract enforcement.

#[\Override] Attribute

Documents that a method intentionally overrides a parent method. Compiler error if the parent method doesn't exist.

json_validate() Function

Validate JSON without decoding — faster than json_decode + error check.

Dynamic Class Constant Fetch

$class::{$constant} — dynamic constant access.

PHP 8.4 Features

Property Hooks

Define get/set behavior directly on properties:

public string $name {
    set => strtolower($value);
    get => ucfirst($this->name);
}

Asymmetric Visibility

public private(set) string $name — readable publicly, writable only privately.

PHP for Magento Specifically

Type Safety

• Use strict types: declare(strict_types=1); in all files
• Type all parameters, return types, and properties
• Use union types for nullable: ?string or string|null

Value Objects

Use readonly classes for DTOs and value objects — common in service layers.

Enums for Status Codes

Replace string/int constants with backed enums for order statuses, product types, etc.

Constructor Promotion in Magento

Magento uses constructor injection extensively — promotion reduces boilerplate significantly.

Best Practices

• Always use declare(strict_types=1);
• Type everything: parameters, returns, properties, constants
• Use readonly for immutable data
• Use enums instead of string/int constants
• Use match instead of switch for value mapping
• Use named arguments for clarity with many-parameter functions
• Use #[\Override] when overriding parent methods
• Follow PSR-12 coding style

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